The Cornish form of this name, Jennifer, has become popular in the English-speaking world.
As an English Christian name, Isaac was occasionally used during the Middle Ages, though it was more common among Jews. It became more widespread after the Protestant Reformation. Famous bearers include the physicist and mathematician Isaac Newton (1643-1727) and the science-fiction writer Isaac Asimov (1920-1992).
It has been common as a given name in the English-speaking world only since the 18th century. A famous modern bearer is American actress Julia Roberts (1967-).
Due to the renown of the saint, this name has been widely used in the Christian world. It has been common in England since the 12th century, though it became a bit less popular after the Protestant Reformation. The name has been borne by five popes and two tsars of Russia.
During the late Middle Ages this name was typically among the five most common for English males (with John, William, Robert and Thomas). It remained fairly popular through to the modern era, peaking in the United States in the 1940s and in the United Kingom a bit later, and steadily declining since that time.
Famous bearers include two German opera composers, Richard Wagner (1813-1883) and Richard Strauss (1864-1949), as well as British explorer Richard Burton (1821-1890), American president Richard Nixon (1913-1994), American physicist Richard Feynman (1918-1988), British actor Richard Burton (1925-1984) and American musician Little Richard (1932-2020).
The name was brought to public attention by Samuel A. Taylor's play Sabrina Fair (1953) and the movie adaptation Sabrina that followed it the next year. This is also the name of a comic book character, Sabrina the Teenage Witch, first introduced 1962 and with television adaptations in 1970-1974 and 1996-2003, both causing minor jumps in popularity. Another jump occurred in 1976, when it was used for a main character on the television series Charlie's Angels.