Guillaume Poyet was a French magistrate born in Angers. After practising successfully as a barrister at Angers and Paris, he was instructed by Louise of Savoy, mother of the king Francis I, to uphold her rights against the constable de Bourbon in 1521. This was the beginning of his fortunes. Through the influence of the queen-mother he obtained the posts of advocate-general (1530) and president of the parliament of Paris (1534), and became chancellor of France in 1538.