Famous Birthdays Apr 5 Bianca Maria Sforza, wife of Maximilian I, Holy Roman Emperor, born in Pavia, Italy (d. 1510) Famous Deaths Apr 6 Pieter Bladelin, Belgian land owner (Middelburg castle), dies Apr 15 Leon B. Alberti, Italian humanist & architect (Philodoxis), dies at 68 Apr 25 Leon Battista degli Alberti, scupltor/musician (Dinner Pieces), dies 1471 History by Year 1473