After rebuilding fortresses that had been destroyed by the Mongols and establishing his authority over the outer towns of the province, he left his brother Mubaraz al-Din Abu'l-Fath in charge of Sistan and traveled to the ordo of Ögedei Khan.
There Shams al-Din was confirmed as the khan's vassal; he was obliged to pay Mongol taxes and to destroy a stronghold in the district of Farah.
In 1253 the town of Nih in western Sistan was besieged by the Mongol commander Neguder.
Shams al-Din led an army in support of Nih and forced Negüder to negotiate for peace in Shahr-i Sistan.
In 1255, a rebellion broke out in the capital, led by his own son Badr al-Din, the problem which became more serious when the Kartid malik of Herat, Shams ud-Din, marched south and seized Shahr-i Sistan.