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Cogs and other 12th century sailing vessels

by Chris.
(Haarlem, Netherland)

How many crew members would it have taken to man a 12th. century cog?

How would such a ship navigate in and out of dock? Would oars be used? Is it possible that smaller oared boats were ever used as tugs?
Were there other styles of ship in use at the time in Europe, capable of transporting, say, men and horses?

Questions, whose answers are presumably highly speculative, from someone who knows very little about sailing, I'm afraid!

Comments for Cogs and other 12th century sailing vessels

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Jan 16, 2010
Right you are, speculative; but the least possible.
by: Han

Hi Chris,

In my article "the Hanseatic trade and the Cog" (History of Sailing Blog)you can find a lot of info on the cog, but none on the points you indicate, because that's where speculation comes in; there's only little documentation on them. However, as I answered Ray Udris in "Docking the tall Ships", they are educated guesses based on experience.

Let's start with the crew-number. By crew I mean a skeleton-crew, the absolute minimum to cover distances from the eastern Baltic to Flanders: my guess is that some 10-15 able seamen would do. But as the cog and it's contemporaries were the only relatively safe long-distance transporters, there must have been quite a number of passengers on board, as well as fighting men to protect ship, cargo and passengers. So the crew-total could run up to several dozens. Speaking of privacy and smell...

Manoeuvring and docking was done in the early cogs (descendants of the Viking knorrs) by oars, but as the ships developed they had too much freeboard to be rowed, so it had to be done with the aid of longboats and kedging. The single sail did not allow for manoeuvring.

The cog's contemporaries in the north-western European waters were, as far as known, all derived from the knorr. They were round-stemmed, and their main home-ports were on the northern French coast and the Cinque Ports on the English southern coast; certainly capable of taking armed men and horses, they were mainly used as coastal vessels and only seldom ventured outside the, then rather limited, English sphere of influence.

You must definitely be interested in history; how did you find us?

I hope to have satisfied your curiosity; you know what to do in case other questions arise.


Jan 16, 2010
Thanks, Han
by: Chris

Thanks, Han. I found the site by googling medieval ships and related stuff.
I'm writing a story, and I need to send two knights and their horses on a voyage equivalent to, say, Southern England to Tangiers, with a minimum of fuss and as few crew members as possible!
The Knorr (much more elegant than the cog!) would need less crew, perhaps: but could it undertake such a voyage?
Somewhere on the internet I also read about a 12th. century Anglo-Norman warship the Nef. Did that also have a square sail?
Lot's of questions occur to me, such as: what ships were the Crusaders using in that century?
Thanks again for the suggestions about how cogs docked. I believe they had shallow, quite flat bottoms too, for beaching with the tide.

Jan 17, 2010
The early nef could do...
by: Han

Hi Chris,
I found the following text on the site of The Oxford Companion to Ships and the Sea:
"Nef, a French ship of the 15th and 16th centuries, a development and enlargement of the cog up to 300–400 tons. They were three masted with square mainsail and topsail on the mainmast and a single square sail on the fore and mizzen, with a spritsail under the bowsprit. Some of the larger nefs carried a bonaventure mizzen with a square sail in addition. They were of carvel construction and were used for trade and war purposes alike."
I think this ship had nothing to do with the cog, for many reasons, but it doesn't suit your time-window.
Also, on
"Nef: 1.Also called a roundship, a single-masted clinker-built ship used in Europe during the middle-ages until the 14th century, for example as transportation for the crusades. Descendant of the Viking longship a Nef still had a side-rudder and was used in Northern regions a century or two longer with a sternpost-rudder."
This last definition exactly fits my description of the cog's contemporaries on The Channel's coasts, the only mistake they make is the descendancy of the longship. As a descendant of the knorr it could certainly be beached on the tide, and was very seaworthy.
The cog had a flat but narrow bottom and was definitely a deep-water ship with it's draught between 6 and 10 feet, so it was not suited to be beached on the tide.
If you want more help with your story, I would gladly provide it; to that end I asked Alex to mail you my e-mail address, if only he has yours. You can mail it to him by using the contact-form.
Hope to hear from you,

May 04, 2010
12th C Cog trading ships
by: Roy

I found your page via Google and a very interesting read indeed.
I am also a writer and am searching for working information on the 12th c. Cog sailing ships but am using quite a lot of license because the ships I'm writing about are sailing out of Bordeaux for Bilbao. These same ships or similar would also I feel sail north to the main Norman ports possibly transporting highly prized Arab horses for breeding.
I would also think that favored paying passengers would be carried in the castle like cabin at the stern. Could you tell me what that cabin was called if known?

May 07, 2010
It's not easy being green (or being called "expert").
by: Han

Hi Roy,

Suddenly I seem to be drowning in a sea of writers dreaming up improbable trips! No blame to you or Chris, just pulling legs ;-)).

For trips between Bordeaux and Bilbao you really need a lot of license: even the ship Chris and I agreed on, the Nef, hardly ever came south of Bordeaux. The best bet as far as I'm concerned would have been a local fisherman, used to the waters of the Golfe de Gascogne, a dangerous area even now for unexperienced sailors.
Horse-transport, in particular high-priced Arabs, couldn't be done in long stages anyway.
My, your, and Chris's problems are the area and the period you chose for your stories: there are hardly any records or artefacts from which to derive information, in contrast to the areas roughly between France, England, Flanders, Holland, Germany and the Scandinavia's.

Favoured passengers, as you call them, would find only scant shelter below the fore- and aft- castles, as they were open at all sides; only after they were integrated in the hull, some two centuries later, you could, with some fantasy, place a cabin there, but the captain/ship-owner would hardly have passengers favoured (=rich) enough to leave his sheltered place.

Hope this meagre reply satisfies your needs. If ever your and Chris's stories are published, may we count on a citation to this site?



May 07, 2010
Green suits you very well...
by: Chris

Han, Roy..
Suddenly more reactions to my question!
If you are interested: my story is finished. I ended up describing a fifty-foot boat more like the old knorr (side steering-oar, square sail etc.) With the help of only six oarsmen and a rather favourable wind, it stayed within sight of the French and Spanish coastlines and got my three characters (one of whom started the voyage as a stowaway beneath the fore-deck) safely to the Afrik shore (about where Tangiers is now).
A lot of licence, I suppose (but it's that kind of story!)
As for 'when it's published'...well, I'm working on it, but.....
Good luck with yours, Roy!
And thanks for everything, Han.

Jul 26, 2010
Editing a novel set in 12th century England could anyone help please?
by: Gaynor

Hello I'm editing a novel set in the mid to late 12th century and the writer describes a ship as a double masted sloop. I've just done a little research and found that sloops were much later and that the vessal of choice would be a cog is this correct? I know very little about boats and even less about 12th century ones and was hoping for some expert knowledge.

Jul 27, 2010
Hands off!
by: Han

Dear Gaynor,

If I was a serious editor I wouldn't want my name connected in any way with a story like that: license is allowed to some extend, but this is going way too far. Comparatively it's like Napoleon being driven to his Waterloo in a Ferrari Formula One.

Hope you'll find a more likely story to edit,



Jul 27, 2010
Thank You
by: Gaynor

Thank you

I'm on it and this is why editors are paid. The story is great, but what a lot of writers do is get caught up in the story and facts be damned,the boat is only mentioned once and the whole scene is about 3 paragraphs, but still I think it's the attention that can make a novel.

This is a great site for someone like myself who needs to know that there are experts out there and that they also care if the ship or clothing is right for the period. When I read a novel the first slip an author makes breaks the spell and it becomes just pages with words on. I work on the idea that all readers are like me and that everyone is an expert on something.

I've changed the boat, or is it ship, I read somewhere that the British Navy has a special designation for which term you use. If questioned now on my change, I can send them here so they can see for themselves.

This is a wonderful site full of information thank you again, I've learned a lot just visiting.

Jul 28, 2010
This has developed into an interesting thread, thanks to all!
by: Han

Hi Chris, Roy and Gaynor,

It was a real pleasure to meet you, I hope your respective projects will meet your expectations.

It is also a pleasure for me to see my work is recognised, for there is no money in it for me. I began this history-project in the hope it would be remunerated in time; the money, if and when it comes, will be sent to welfare-organisations for sailors in need and lifeboat-organisations. Alas, that time has not yet arrived, but I hope it will before I can't write any more.

Maybe we'll meet again.



Jan 17, 2011
cogs and novels
by: prue Batten

I have just found this site and am so impressed with the information provided.

I have two passengers leaving Calais in the late 12the century, sailing across the Channel, to finish up off Harwich.

I chose a cog with oarsmen (how many?), am assuming one sail, an open hold and the interior of the hull in view? Would a passenger be able to sit in the hold leaning against the ribs? In addition, how many could fit in the hold at any one time?

I also wondered, apart from the stars, how a navigator coped? What if there was a fog? would they just put out some sort of sea anchor, to slow them down and hope for the best until visibility improved?

So many questions!

Jan 20, 2011
A cog again? There? And why a cog?
by: Han

Dear Prue,

As I argued more times than I like to remember, the cog was a Hanseatic League ship; this league, based in the Friesian and Saxon parts of the nowadays northern German and north-eastern Dutch territories, had an important influence as far south-west as London but hardly any further.
In the area you chose for the crossing, you have to consider the Dunkirk pirates, the power of the Hanseatic League north of the Thames and the fact that this area (The Channel) has to be regarded as the (Norman) Cinque Ports area, where the Nef (Norman for "ship") was the ship most likely used: a descendant of the Norman knorr, and definitely a different kind of ship.
If this Nef was partly or fully decked, no one would have liked to be in the hold together with the cargo: no room to stand, bilge-water sloshing around, an unbearable stench. Passengers and crew alike were on deck and stayed there, whatever the weather; they were used to that in those days. Long trips were divided in short stages anyway.
The number of oarsmen is not important at all: the crew rowed when manoeuvring with the one square sail was impossible; sailing was the way to cover any important distance.
About navigation: knowledge of the use of the stars and a crude form of compass was only introduced much later with the infusion of Mediterranean and Arab science. Only intimate (fisherman's) knowledge of sea-currents, colours, smells and tastes of water, sea-bottom composition and weather-systems brought them where they wanted. And mind very well: even my own father, who died only 40 years ago, navigated across the North Sea with this same ancient knowledge.
Fog did not bother anybody, other traffic was sparse and speeds were slow.

Hope to have met your requirements,



Jan 20, 2011
Prue Batten
by: Prue Batten

Thank you so much for your succinct comment. You have in fact given me layers of the story that i would not have been able to introduce otherwise. In my rough draft, my boatsman had knowledge of currents and water colour and was verging on pirate, if not fisherman. I will research the nef in detail.

My only mistake was to have my female passenger in the hold. Shall now move her on deck.

I really am most grateful for this and plan to use this site more often for reading and research.

Best wishes.

Jan 21, 2011
Differences cog-nef
by: Han

Dear Prue,

Thanks for your kind words. Being praised feels like a nice and warm bath and I really love it.

Most hits you'll get when googlin' for nef will be of the ghastly posh silver centerpieces on dining-room tables with party-babbling people around them. I'll give you the main differences in short:
Cogs had a straight stem- and a straight stern-post; from the latter hung the stern-rudder, a novelty then and characteristic for the cog.
The early nef as meant by you was a relatively small ship with curved stem- and sterposts and a side-rudder.
Most people see them as the same kind of ship because the rig was, apart from small details, the same: single-masted, square-rigged.
For the (early) nef I prefer the use of the description "ship of the Cinque Ports", as nef means nothing else but "ship". Spaniards, Portuguese and French sailors used the related word nao with the same meaning, but mostly meant much bigger ships, which modelled for those monstrous silver bogus-ships (even on wheels, can you imagine?).

I think with this you can save on your research-time.

Regards, Han.

P.S.: I still don't understand this sudden international writer's rush for the 12th century and trips south of England.

Jan 23, 2011
Prue Batten
by: Prue Batten

the only thing i can think of is that historical fiction is immensely popular currently and from my own point of view, anything from the 12-16th century is always readable.

I now have another question, right away from cogs and wonder of you are able to answer this. What would have been the European version of the canoe or kayak in the twelfth century. So far, basic research has only talked about the craft in relation to the Inuits in Canada and North America.

Jan 23, 2011
Canoe & Kayak
by: Han

Hi again, Prue!

"...from my own point of view, anything from the 12-16th century is always readable", you said. Provided the author is a talented narrator, I presume? I've no doubt you are, although I had never heard of you before, sorry...

The canoe, as a more or less refined dug-out log, has always been part of European fishing tradition. All I knew and found by research is to be read here:

Hope this is what you are looking for!

May 08, 2011
by: Rick

Hello Han
I have just come across the exchange about nef/cog/knorr and have paused to wonder. Where in this line of development did the berlinn fit, was it a dead end? and secondly, on present available information what type did the Newport ship belong to?
Thank you

May 10, 2011
Identification Newport ship; Berlinn unknown to me...
by: Han

Hi Rick,

Interesting question!
The Newport ship seems (to humble me) to be an in-between: on the one side some Nordic characteristics: clinker-built, coin under main mast; on the other: three-masted with the possibility of a lateen-sail on the mizzen, which indicates Mediterranean influences.
I'm inclined to indentify it as a later, bigger Nef, leading to the development of the Carrack.
The berlinn you ask about is nowhere to find in the crypts of my ageing brain, nor can I find it in my library or on the internet. If you have a picture, please mail it to and I'll do my best for you.

All the best for now,


May 13, 2011
by: Rick

Hi Han,
The berlinn (as far as I can ascertain) was a ship type used in Celtic areas 12th and 13th centuries. As far as I can make out there has been one replica built the "Lord of the Isles", the group that built her do have their own web site but again they seem to have not been very active over the last three or four years, possibly through lack of funding. The web address is
Hope this is useful.
All good wishes

May 30, 2011
Further Questions about Cogs
by: Ardra

What a delight to have found this site! I'm currently writing a historical-fiction with heavy elements of satire. Despite humor throughout the story, the main plot is serious, and I've learned through the process of writing that doing my research on historical specifics has drastically enriched the story.

The story takes place in 1214 (in between the 4th and 5th crusades) and includes a section in which two parties journey across the Mediterranean from Zara to Alexandria. One party is a small group of protagonists who find passage with Venetian traders (daft enough to cross the sea instead of skirting the coast). The other group is a force of conscripts, knights, and some cavalry that may include from 300-800 men (a majority of these die when one of the transport ships sinks). Details I've kept in mind so far are the aforementioned stink, dangerous storms, rats, superstition regarding sea travel, and deaths caused by constant sea-sickness.

A few important questions: is the cog the historically accurate ship for this time period? About how many men (and horses) could be transported on such-said ship, and therefore how many ships may have been needed to transport that force? Is it even remotely conceivable that there would be sailors willing to sail across the Mediterranean to get to Alexandria more quickly rather than skirt the coast, if given enough financial incentive? Thank you for any assistance.

May 31, 2011
Thanks Rick,
by: Han

Hi again,

Your link gives me a better idea about what the bIrlinn must have been: surely a descendant of the knorr, it must have been conceived when the cog and it's stern-rudder was known. So I would place it in the 13th century if not later. I have never seen anything like it, so thank you!
I'll try to contact the people of the site, maybe we can have a fruitful discussion (at least for me, I love to learn).

Maybe till later,

Regards, Han.

May 31, 2011
I love satire!
by: Han

Dear Ardra,

I haven't the slightest clue where Zara lies on the Mediterranean coast, but I can assure you that a lot of overland trips were much more dangerous than a sea-cruise, certainly in those times.
Now about that large army (3-8 hundred men, horses included): you need a small fleet, as I estimate a total crew of several dozens (see earlier comments, horses excluded) per ship; if you want to drown half of them, you don't talk about ONE transport ship but, let's say, ten.
The cog is the ship fitting for that era, but certainly NOT in the eastern Mediterranian and used by Venetians. Many sources indicate the cog as the ship used for the crusades, but that's because all English sources mix the cog up with it's contemporaries.
Safest way for you to describe the ships as just ship, single-masted, about 50 feet long, square sailed and sometimes rowed.
If you need further info (or educated guesses) please say so.



May 31, 2011
Re: Response from Han
by: Ardra

Thank you very much : ). Zara is a port on the eastern coast of the Adriatic (Dalmatia). It had just been reclaimed by the Venetians in a bloody seige that took place at the beginning of the Fourth Crusade. It is currently called Zadar in modern Croatia.

You're definitley correct about the land journey, which I discovered yesterday is why the crusade force had to bargain with the Venetians to amass a fleet. Transport would require enough ships that maybe my antagonist is forced to leave part of his army behind to A) Afford the costs of chartering passage and B) Get going in a reasonable amount of time. I'll fidget with the numbers a bit so I'm not straining credulity too far.

As far as a merchant ship goes, would that be similar to the large Venetian ship you described or different? The type mostly used for transporting rugs, ceramics, spices, textiles, etc.

Jan 10, 2013
So many stories!
by: Phil

Thanks for your very useful site though I am dismayed to find so many other writer are researching in what I, when I began, imagined might be relatively unexplored territory for a narrative. Yikes!

Sep 19, 2014
Yet another historical novel!
by: Hilary Green

Hi Han,
I've just discovered your fantastic site. I think you may be able to answer the question I am struggling with. My question is about ships trading between Chester and Dublin around the time of the Norman conquest. I assume the cog would be the right type of vessel, but I don't know how long it would have taken to complete the trip. What happened if they met bad weather and could not complete the crossing in one day? And, if the hold was full of cargo, where were the crew - on thwarts above it, or along the sides of the ship? How many would there be?
I shall be most grateful for your help.

Sep 19, 2014
by: Prue

Dear Hilary,

If you read right back in the comments, you will see that Han has addressed the issue of the cog. It was in fact a Hanseatic league vessel.

Correct me if I am wrong, but the Hanseatic League didn't exist at the time of the Norman Conquest, did it?

Best wishes with your research. Han helped me wonderfully when I was researching the first book in The Gisborne Trilogy. I highly recommend his expertise.

Sep 20, 2014
Query from another novelist
by: Hilary

Hi Han.
I thought I had posted this yesterday, but although I got an email today saying there was a new comment I can't find either my original post or the new comment.
My question is this: A vessel trading between Chester and Dublin in the early 12th C would presumably be a cog. How long would it take to complete the voyage? What would happen if bad weather stopped them from completing it in one day. I'm assuming that they always moored up somewhere for the night. I've looked at pictures of cogs but I can't work out where the crew sat. On thwarts above the cargo, or round the sides of the ship?
I'll be grateful for any information.

Sep 20, 2014
What is gong on?
by: Hilary

I don't understand this! I keep getting emails saying there is a new comment but my question is not on the site and there are no new comments, as far as I can see.

Sep 20, 2014
Hilary Green and cogs
by: Prue

Hilary, I can see your original question and I commented. I don't believe Han has replied as yet. That said, i am sure if you read right back to the beginning of this thread, you may find some helpful information. It yes back to 2010 and further.

Mar 13, 2015
Some input on cog crew estimates NEW
by: Anonymous

I too write histrical fiction and stumbled across this forum as a result of Googling.

Just wanted to share what I found out on a website relating to crews during the naval Battle of Sluys, 24 June 1340 (RE:

The contributor estimates King Edward III's fleet 'at perhaps 300 to 400 sail. The ships (cogs) were small, most having a regular crew of 5 or 6, with an additional fighting force of 10 to 15 archers and men-at-arms.' Unfortunately we do not have recorded numbers for the English at Sluys but if we take the largest numbers here we might estimate the king sailed with 8,400 personnel.

As there was no standing navy at this time Edward's 'fleet' was commandeered from private English merchants. Luckily for the merchants, reports suggest no losses on the English side so let's presume he could return them all (he actually managed to capture a few French vessels too!)

I also understand that during or after the War of the Roses (1455-1485) when a standing navy was developed the cogs became larger... so that... er, blows my earlier figures out of the water somewhat!

Hope my info helps and thanks for all yours

May 07, 2015
Types of wood used NEW
by: Gergely

I'm also an aspiring writer who found this page through google and is really grateful for the wonderful information provided here :D
I would like to ask you about the types of wood used to make 13th century ships. I'm interested in both northern (Hanseatic) and southern ship types, and any information regarding shipbuilding of the time (amount of time to build 1 knarr for example, and total wood used in the process).
Yours sincerely,

May 07, 2015
Still hoping for a response from Han NEW
by: Hilary Green

I posted a question many weeks ago and though I got an answer from Prue Batten it didn't really give me the information I was seeking. The main question was about the time it would take for a cog to sail from Chester to Dublin. Am I wrong using a cog for this journey at all? What would a coastal trading vessel have been called in England shortly after the Norman Conquest?
I would also be interested to know how long it would take for a cog (I think that is correct for this context) to sail from Bruges to Bordeaux. Several days I assume, but would it be possible to make more than one round trip in a season?
Rading more of the posts regarding transport in the Med at this period I see no mention of the galley. Did they not exist then? What sort of boats would the Arab pirates have used?
So many questions! But I shall be very grateful if you can answer them. I am a published writer and I will defintiely give you a credit when the book comes out.

May 07, 2015
by: Prue Batten

Hilary, I am wondering if Han may not be well, as it is a long long time since he answered any queries. I doubt he would care over much about being credited in acknowledgements anyway. He seemed to respond to people because he enjoyed it.

I have found that galleys were very much a part of life in the twelfth and thirteenth centuries and that 'peireates' used them. Not sure what timeframe you are writing about but there are quite a secondary resources on Mediterranean medieval ships.

May 08, 2015
Thanks NEW
by: Hilary Green

Thanks, Prue. I did wonder if Han was no longer operational but I suddenly astarted getting e-mails saying 'new comment' so I came back to the site to see what was going on. I'm working on the prequel to the book you read 'God's Warrior' - I don't know if you remember it. Anyway, There's a lot of helpful info from other poeple on the site. so it was worth a look. The one thing nobody seems to ask is 'how far,given reasonable weather conditions, could a cog sail in a day.' never mind, I'll try other sorces. Hope your book is going well.

Feb 11, 2016
Sailing vessels of the 12th century NEW
by: Mike


I am writing a novel and it centers around the early 12th century. Were there any large sailing vessels built around this time? In my novel and my imagination, I have created a very large sailing vessel that is powered by wind, hence the sails. Perhaps there were some prototypes being built that did not succeed on the seas? As I was writing, I thought it best to research a bit about my vessel that sails from Alexandria, Egypt up the Adriatic to the port of Venice. Any help would be great and you would be mentioned in the special thanks page of my novel.
Best regards,

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