Shams-uddin was the son of Rukn-uddin Kart I and a Ghurid princess.
During his stay in India he met the Sufi Saint Baha-ud-din Zakariya at Multan in 1247–8.
Later he visited the newly crowned Mongol ruler Möngke Khan in Mongolia, who gave him control over much of the Khurasan, and possibly land as far as the Indus.
He again visited Abaqa Khan, accompanied by Shams-uddin the Sahib Diwan, in 1276–7, and this time the former good opinion of the Mongol sovereign in respect to him seems to have been changed to suspicion, which led to his death, for he was poisoned in January 1278, by means of a water-melon given to him while he was in the bath at Tabriz.
Abaqa Khan even caused his body to be buried in chains at Jam in Khurasan.