first printed in Standfast 2014
How sad it is that the myopia of Oxford academics prevents their seeing past Hadrian's Wall.
In the "Oxford Names Companion" for the Scots given name "Jock" they say "Scottish: variant of Jack". They then pile it on by saying that "Jocky" is a pet form. What nonsense. We all know that Jockeys ride horses. Interestingly the Shorter Oxford Engish Dictionary has nothing at all to say about the etymology of the word "jockey".
"Jockey" is none other than the Gaelic given name "Eochaid(h)" - which means "Rider/horseman" (from Ech = horse). There was even a Scottish King Jockey (ie Eochaid) who ruled with Grig in the period 878-889. Many Irish kings also bore this name. [In modern day Ireland one variant appears to be Haughey.]
So Jock is not a variant of Jack however much it may have come to be used in this way - and Jock, not Jocky, is the pet form.
Jock became a generic name for a Scotsman because in feudal times the Scots bred horses which they sold in England - thus most English people's personal knowledge of Scots was as horse dealers.
And it turns out that this is all down to the Grants......!
It was in 1380 that the illegitimate son of Robert Grant the Ambassador (9th chief), also called Robert, was given a safe conduct to trade in England. He was the founder of the MacRobbie Grants who held Stratha'an where the horse breeding took place. He and his family held a monopoly of the horse trade in England for a hundred years and were intimately connected with the later Plantagenet kings of England.