In America, this name received a boost of popularity in 2000 when a character bearing it began appearing on the television series The West Wing.
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.
There was a medieval English form of this name, Helewis, though it died out after the 13th century. In the 19th century it was revived in the English-speaking world in the form Eloise.
Due to the renown of the saints by this name, Gregory (in various spellings) has remained common in the Christian world through the Middle Ages and to the present day. It has been used in England since the 12th century. A famous bearer from the modern era was American actor Gregory Peck (1916-2003).
Jonah's story was popular in the Middle Ages, and the Hellenized form Jonas was occasionally used in England. The form Jonah did not become common until after the Protestant Reformation.
As an English name it was not used until after the Protestant Reformation. It was utilized by George Eliot for the title character in her novel Silas Marner (1861).