Watch List notes:

Abbasid, al-Mahdi, AH 158-169 (AD 775-785). AR dirham (2.94 gm; 25 mm). Madinat al-Salam (Baghdad) mint. Dated AH 161. With his name as al-Khalifa al-Mahdi. Album 215.1. Minor scratches on the reverse. Choice AU with some luster.