Piccolomini, Alessandro one of the most distinguished of Italian prelates of the 16th century, was born at Siena in 1508. He sprang from the same family as pope Pius II (q.v.). and by his piety, modesty, and scholarship gained great renown; but no events of his life are particularly worth recording. He deserves to be remembered for the wide extent of his writings, and the esteem in which they were held by his contemporaries and immediate followers. He died in 1578. He was of an original turn of mind, and his writings are almost all in Italian, so that he is among the earliest of those who endeavored to raise the character of vernacular literature by treating all branches of knowledge in modern tongues. His commentaries on Aristotle were prized for their good sense, and for their abandonment of most of the scholasticisms by which that philosophy was disfigured by commentators. He advocated in 1578 the reformation of the calendar, which was afterwards adopted. In his book on the fixed stars and the sphere he adopts the mode of designating the stars by letters — a small matter, but one which makes the greater part of the immortality of Bayer, and to which the diagrams of Piccolomini establish his prior claim. His works are of a most miscellaneous character — astronomy, physics, comedies, sonnets, morals, divinity, and commentaries on Aristotle. De Thou speaks in strong terms of the rare union of diversity and depth which his acquirements presented. For a list of his most important works, and an estimate of them, see Fabiani, Vita d' Aless. Piccolomini (Vienna, 1749, 1759, 8vo); Ughelli, Italia Sacra, s.v.; Tiraboschi, Storia della letter. ital. volume 7, part 1, page 506; Niceron, Memoires, volume 23, s.v. — Hoefer, Nouv. Biog. Gen. s.v.