With Al-Mutawakkil perishes the last semblance of Moorish unity. The emirs again become independent princes, but the Christian encroachment has been such that none of them has any considerable power, or territory, except =Muhammed (I) Ben Al-Akhmar=, who in 1238 founds the kingdom of Granada. 1238 Reduction of Valencia by James I. 1245 Muhammed cedes the town of Jaen to Ferdinand III of Castile, and becomes a tributary of Castile. 1248 Surrender of Seville to Ferdinand. Other cities follow. 1253 Muhammed founds the Alhambra at Granada. 1254 Alfonso X of Castile conquers many Moorish cities in southern Spain. 1261 Muhammed attempts to cast off the yoke of Castile, and encourages Andalusia and Murcia to rebel. 1264 Peace made with Castile. Granada is again tributary. 1266 Capture of Murcia by James I. All Spain is now Christian, except Granada. 1273 The Merinids arrive in Spain, from Africa, to assist the Moors. Death of Muhammed. His son =Muhammed II= succeeds. He makes a treaty with Alfonso X of Castile. 1275 Abu Yusuf, king of the Merinids, brings a large army to Spain. The Castilians and Aragonese are defeated, but Alfonso checks the conqueror. 1278 The Merinids drive the remaining Almohads from Spain. 1281 Alfonso allies himself with the Merinids to suppress a revolt in Castile. 1285 Death of Abu Yusuf. 1292 The Castilians take Tarifa, after defeating the Moorish fleet at Tangiers. 1294 Unsuccessful attempt of the Moors to recapture Tarifa. The Merinids finally withdraw from Spain. 1302 Death of Muhammed. His son =Muhammed (III) Abu Abdallah= succeeds. 1308 Capture of Gibraltar by Ferdinand IV of Castile. Treaty with the Granadans, who renounce some of their territory. 1309 Revolt in Granada. Muhammed is compelled to resign the throne to his brother =Nasir Abu Abdallah=. The rebellion continues, and 1313 Nasir is deposed by his nephew =Ismail Feraj=. He has constant wars with the Christians. 1319 Great defeat of the Castilians in Granada. 1325 Assassination of Ismail by one of his officers. His son =Muhammed IV= succeeds. 1328 Reduction of Baena by Muhammed. 1333 Muhammed obtains an army of Merinids from Africa, who retake Gibraltar. Alfonso XI attempts to retake. Muhammed comes to relieve the Merinids, but they assassinate him. His brother =Yusuf Abul-Hagiag= succeeds. 1340 Yusuf besieges Tarifa, with the assistance of Merinid auxiliaries. Alfonso IV of Portugal, and Alfonso XI of Castile, relieve the town and administer a crushing defeat to the Moors, on the river Guadacelito (Salado). 1343 Surrender of Algeciras to Alfonso of Castile, who makes ten years’ treaty of peace with Yusuf. 1354 Assassination of Yusuf by a madman, while at prayer. His son =Muhammed V= succeeds.