Simone Martini and Lippo Memmi

His brother-in-law was the artist Lippo Memmi (1291 – 1356), who is noted as the foremost follower of Martini’s work. Together, between 1329 and 1333 they executed one of the masterworks of International Gothic painting, the Annunciation Altarpiece for the Sienese church of Sant'Ansano in Siena, now in the Uffizi. It is said that Memmi painted the two Saints, Ansano (Patron Saint of Siena) and Giulitta, while Martini painted the Virgin and the Angel Gabriel. (Kren and Marx, Web Gallery of Art)

(This text is adapted from the www.wikipedia.org entries on Simone Martini and Lippo Memmi, available under GNU Free Documentation License.)