Complex sentence: According to Runciman, Joscelin seized former Antiochene territories from Il-Bursuqi, governor of Mosul, and Bohemond refused to cede Azaz to Joscelin, although Roger of Salerno had promised it to Joscelin as the dowry of his second wife, Maria of Salerno.
Split into simpler sentences: According to Runciman, Joscelin seized former Antiochene territories from Il-Bursuqi, governor of Mosul. Furthermore, Bohemond refused to cede Azaz to Joscelin, despite the fact that Roger of Salerno promised it to Joscelin as the dowry of his second wife, Maria of Salerno.