The name Jack tar began being used for British sailors around the turn of the 18th century. The earliest that I can find it in print is from The Female Tatler, a short-lived magazine which ran from 1709 to 1710. The August 1709 issue described a motley crew of people as:
…his Grace and my Lady Dutchess, Jack Tar, and Mrs. Top-gallant-Sail, with every Coffee-Man, and his Wife.
The derivation of ‘Jack tar’ seems fairly straightforward. Firstly, let’s look at ‘Jack’.
In England, since the 14th century, ‘Jack’ has been a synonym for ‘the common man’, as is ‘Jock’ in Scotland. An early example is found in John Gower’s Middle English poem Confessio Amantis, 1390:
Therwhile he hath his fulle packe,
They seie, ‘A good felawe is Jacke’.
Whenever a name was needed for any stereotypical common fellow, Jack was chosen. Examples of this are:
Jack of all trades
Jack the giant killer
Jack in the box
Jack Robinson
Jack the lad
and so on…
A sailor was the common man at sea. Jack took the ‘common man’ part. ‘Tar’ was chosen to refer to all things sailor-like.
This was for good reason, sailing ships of the 18th century reeked of tar. Anyone visiting Nelson’s flagship the HMS Victory in Portsmouth Dockyard will notice the strong smell of tar even now, many years after the ship last took to sea.
Tar was used as waterproofing on many parts of the ship – between the planking of the hull and deck, on ropes and on sheeting. Sailors hands, hair and clothes would become smeared with tar. They used tar to braid their pigtails and to waterproof their canvas hats and trousers. No wonder really that a sailor would be called ‘tar’ – the perfume of it would have been unmissable.
The extended form ‘Jolly Jack tar’ began to be used from around the turn of the 19th century. Here’s an early example from The Edinburgh Advertiser, April 1802:
Two jolly Jack tars exhibited a complaint at Bow-street on Saturday evening of having severally been robbed.
This doesn’t seem to be because sailors were thought to be especially jovial. Jolly, or jollie, was the name given to a royal marine. This is recorded in Admiral W. H. Smyth’s The Sailor’s Word-Book: an alphabetical digest of nautical terms, 1867:
Tame jolly, a militiaman: royal jolly, a marine.
The above book is an invaluable and exhaustive list of the words used by sailors in the 19th century.
It seems that sailors weren’t especially fond of the name Jack tar as, although ‘Jack’ is mentioned in the book in many contexts, ‘Jack tar’ doesn’t appear. What is there is what sailors preferred to call themselves – ‘Jack afloat’.
See also: ‘Jack’ phrases.