Birthdays in History Sep 1 Henry II, Prince of Condé, French nobleman (d. 1646) Sep 8 Marin Mersenne, French mathematician (Number of Mersenne), born in Oizé, Maine, France (d. 1648) Deaths in History Sep 4 Robert Dudley, English Earl of Leicester, favourite of Elizabeth I, dies at 87 1587 On This Day in History by Year 1589