Cosimo I de' Medici, Grand Duke of Tuscany
Angelo Nicolini was born in Florence in 1505, the son of Matteo Nicolini. He attended the University of Pisa, becoming a doctor of both laws in 1523. In 1530, he married Alessandra di Vincenzo Ugolini; the couple had four children before his wife's death in 1550. He was a counselor to Cosimo I de' Medici, Grand Duke of Tuscany, who entrusted him with many important missions and made him a senator. He was the ambassador of Duchy of Florence to the court of Pope Paul III, and then, in 1538, to Charles V, Holy Roman Emperor. He became governor of Siena in 1557.