Balansiyya had a rebirth of sorts with the beginning of the Taifa of Valencia kingdom in the 11th century. The town grew, and during the reign of Abd al-Aziz a new city wall was built, remains of which are preserved throughout the Old City (Ciutat Vella) today. The Castilian nobleman Rodrigo Diaz de Vivar, known as El Cid, who was intent on possessing his own principality on the Mediterranean, entered the province in command of a combined Christian and Moorish army and besieged the city beginning in 1092. By the time the siege ended in May 1094, he had carved out his own fiefdom—which he ruled from 15 June 1094 to July 1099. This victory was immortalised in the Lay of the Cid. During his rule, he converted nine mosques into churches and installed the French monk Jérôme as bishop of the See of Valencia. El Cid was killed in July 1099 while defending the city from an Almoravid siege, whereupon his wife Ximena Díaz ruled in his place for two years.

What was El Cid's real name?