In Brazil, Duarte is an extremely rare first name, whereas the form Eduardo is very popular. This may be due to the fact that Duarte is a common surname.
The name was first borne by king Duarte I (1391 – 1438), who was the 11th king of Portugal. His unusual name was given in honour of Edward III of England, who was the grandfather of his mother Philippa of Lancaster. Subsequently this name was popular in the Portuguese Royal Family. [noted -ed]