Abu Al-Hasan 'Ali ibn 'Othman (c. 1297 – 24 May 1351), (Arabic: أبو الحسن علي بن عثمان‎) was a sultan of the Marinid dynasty who reigned in Morocco between 1331 and 1348. In 1333 he captured Gibraltar from the Castilians, although a later attempt to take Tarifa in 1339 ended in fiasco. In North Africa he extended his rule over Tlemcen and Ifriqiya, which together covered the north of what is now Algeria and Tunisia. Under him the Marinid realms in the Maghreb briefly covered an area that rivaled that of the preceding Almohad Caliphate. However, he was forced to retreat due to a revolt of the Arab tribes, was shipwrecked, and lost many of his supporters. His son Abu Inan Faris seized power in Fez. Abu Al-Hasan died in exile in the High Atlas mountains.