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.
After the Norman Conquest this name became common in England. It was revived in the 18th century, perhaps in part due to Matthew Prior's 1709 poem Henry and Emma [2]. It was also used by Jane Austen for the central character, the matchmaker Emma Woodhouse, in her novel Emma (1816).
In the United States, it was third in rank in 1880 (behind only the ubiquitous Mary and Anna). It declined steadily over the next century, beginning another rise in the 1980s and eventually becoming the most popular name for girls in 2008. At this time it also experienced similar levels of popularity elsewhere, including the United Kingdom (where it began rising a decade earlier), Germany, France, Italy, Spain, Scandinavia and the Netherlands. Famous bearers include the actresses Emma Thompson (1959-), Emma Stone (1988-) and Emma Watson (1990-).
In the English-speaking world this name is more commonly given to girls. This is due to the American actress Alexis Smith (1921-1993), who began appearing in movies in the early 1940s. It got a boost in popularity in the 1980s from a character on the soap opera Dynasty.