Toghan-Shah was the son of Mu'ayyid al-Din Ai-Aba and succeeded him in 1174 when the latter was captured and executed while fighting in Khwarezm.
With a contingent of Qara Khitai troops, Sultan Shah established a power base in Khurasan and soon turned on Toghan-Shah.
The latter was incapable of withstanding Sultan Shah's attacks, and as a result he lost Tus to him in 1181.
[1] For the rest of Toghan-Shah's reign he continued to suffer from Sultan Shah's raids.
Attempts to enlist support against him from Tekish, the current Khwarezmshah, or from the Ghurids, who had given him a princess in marriage, were unsuccessful.