American writers Jack London (1876-1916) and Jack Kerouac (1922-1969) were two famous bearers of this name. It is also borne by the actor Jack Nicholson (1937-) and the golfer Jack Nicklaus (1940-). Apart from Nicklaus, none of these famous bearers were given the name Jack at birth.
In the United Kingdom this form has been bestowed more frequently than John since the 1990s, being the most popular name for boys from 1996 to 2008.
The English names Jacob and James derive from the same source, with James coming from Latin Iacomus, a later variant of the Latin New Testament form Iacobus. Unlike English, many languages do not have separate spellings for the two names.
In England, Jacob was mainly regarded as a Jewish name during the Middle Ages [1], though the variant James was used among Christians. Jacob came into general use as a Christian name after the Protestant Reformation. In America, although already moderately common, it steadily grew in popularity from the early 1970s to the end of the 1990s, becoming the top ranked name from 1999 to 2012.
A famous bearer was Jacob Grimm (1785-1863), the German linguist and writer who was, with his brother Wilhelm, the author of Grimm's Fairy Tales.