Steffani, Agostino, an Italian composer, was born at Castel-franco, government of Venice, about 1655. In his youth he was entered as a chorister at St. Mark's, Venice, where a German nobleman, pleased with him, obtained his discharge, took him into Bavaria, gave him a liberal education, and when he arrived at the proper age got him ordained. He then took the title of Abate, by which he is now commonly known. His ecclesiastical compositions soon became numerous, and attracted the notice of Ernest, duke of Brunswick, who invited him to Hanover, and made him director of his chamber music. Steffani was also a statesman, and had a considerable share in concerting with the courts of Vienna and Ratisbon the scheme for erecting the duchy of Brunswick-Luneburg into an electorate, for which service the elector assigned him a handsome pension, and pope Innocent XI gave him the bishopric of Spiga. He died at Frankfort in 1730.