As an English name it can also derive from the month of August, which was named for the Roman emperor Augustus.
The popularity of the name Eleanor in England during the Middle Ages was due to the fame of Eleanor of Aquitaine, as well as two queens of the following century: Eleanor of Provence, the wife of Henry III, and Eleanor of Castile, the wife of Edward I. More recently, it was borne by first lady Eleanor Roosevelt (1884-1962), the wife of American president Franklin Roosevelt.
It has been used as a Christian given name in the English-speaking world since the Protestant Reformation. A famous bearer was Nathan Hale (1755-1776), an American spy executed by the British during the American Revolution.
This was a common name in classical Greece, and, due to both the saints who carried it and the favourable meaning, it came into general use in the Christian world, being especially popular among Eastern Christians. It was however rare in Britain before the 19th century. Famous bearers include three tsars of Russia (in the Russian form Fyodor) and American president Theodore Roosevelt (1858-1919).
In England the name was used by the Normans and became very popular due to Saint Thomas Becket, a 12th-century archbishop of Canterbury and martyr. It was reliably among the top five most common English names for boys from the 13th to the 19th century, and it has remained consistently popular to this day.
Another notable saint by this name was the 13th-century Italian philosopher and theologian Thomas Aquinas, who is regarded as a Doctor of the Church. Other famous bearers include philosopher Thomas Hobbes (1588-1679), American president Thomas Jefferson (1743-1826), novelist Thomas Hardy (1840-1928), and inventor Thomas Edison (1847-1931).