A golden age of political and architectural activity in Bosra began during the reign of Ayyubid sultan al-Adil I (1196–1218). One of the first architectural developments in the city was the construction of eight large external towers in the Roman theater-turned-fortress. The project began in 1202 and were completed in 1253, towards the end of the Ayyubid period. The two northern corner towers alone occupied more space than the remaining six. After al-Adil's death in 1218, his son as-Salih Ismail inherited the fief of Bosra who resided in its newly fortified citadel. During Ismail's rule, Bosra gained political prominence. Ismail used the city as his base when he claimed the sultanate in Damascus on two separate occasions, reigning between 1237–38 and 1239–45.