AIDIN. (1) A vilayet in the south-west of Asia Minor in cluding the lower part of the Maeander valley. (2) The prin cipal town of the vilayet about Tom. E.S.E. of Smyrna. It was taken by the Seljuks, Aidin and Mentesh, late in the 13th century, and about 139o, when ruled by Isa Bey, a descendant of the first named, acknowledged Ottoman suzerainty. In the Seljuk period it was only a secondary city under the provincial capital, Tireh. In the 17th century it came under the power of the Karasmans of Manisa and remained so till about 182o. Aidin is on the Smyrna-Dineir railway. On a neighbouring height are still to be seen the ruins of the ancient Tralles (q.v.). Aidin itself suffered severely in the Greco-Turkish conflict of 1919-1922. Pop. 70.307.