An ancient city of Mysia, in Asia Minor; founded by a colony of Greek emigrants in 3rd century B.C., and eventually the centre of a province of the name, which was subject for a time to Macedonia, but threw off the yoke and became independent, till it became a Roman province by bequest on the part of Attalus III. in 133 B.C. The city possessed a library second only to that of Alexandria, contained one of the seven churches mentioned in the Revelation, and gave its name to parchment, alleged to have been invented there.