This name was fairly common in France, England and the United States in the early 20th century. It became quite popular in France and England at the end of the 20th century, just when it was at a low point in the United States. It quickly climbed the American charts and entered the top ten in 2014.
As an English name it has been in use since the Middle Ages, originally in the form Clare, though the Latinate spelling Clara overtook it in the 19th century and became very popular. It declined through most of the 20th century (being eclipsed by the French form Claire in English-speaking countries), though it has since recovered somewhat.
As a given name, Diana has been regularly used since the Renaissance. It became more common in the English-speaking world following Walter Scott's novel Rob Roy (1817), which featured a character named Diana Vernon. It also appeared in George Meredith's novel Diana of the Crossways (1885). A notable bearer was the British royal Diana Spencer (1961-1997), the Princess of Wales.
Among Christians, this name was originally more common in Eastern Europe. It was borne in the 12th century by Saint Elizabeth of Hungary, a daughter of King Andrew II who used her wealth to help the poor. In medieval England it was occasionally used in honour of the saint, though the form Isabel (from Occitan and Spanish) was more common. It has been very popular in England since the reign of Queen Elizabeth I in the 16th century. In American name statistics (as recorded since 1880) it has never ranked lower than 30, making it the most consistently popular name for girls in the United States.
Besides Elizabeth I, this name has been borne (in various spellings) by many other European royals, including a ruling empress of Russia in the 18th century. Famous modern bearers include the British queen Elizabeth II (1926-2022) and actress Elizabeth Taylor (1932-2011).
Famous bearers include the uncrowned English queen Lady Jane Grey (1536-1554), who ruled for only nine days, British novelist Jane Austen (1775-1817), who wrote Sense and Sensibility and Pride and Prejudice, British primatologist Jane Goodall (1934-), and American actress Jane Fonda (1937-). This is also the name of the central character in Charlotte Brontë's novel Jane Eyre (1847), which tells of Jane's sad childhood and her relationship with Edward Rochester.