Complex sentence: Ariq Böke convinced Alghu to take control of the Chagatai Khanate in Central Asia whose khan, Qara Hülëgü, had recently died.
Split into simpler sentences: Ariq Böke convinced Alghu to take control of the Chagatai Khanate in Central Asia. Chagatai's khan, Qara Hülëgü, had recently died.