Abu'l-Makarim Rukn al-Din Ahmad b. Muhammad al-Simnani was born in 659/1261 in the village of Sufiabad near Semnan into a prominent family tied to the Ilkhanids. After renouncing court life he joined the Kubrawiyya tradition and founded its Rukniyya branch, becoming known for his critique of Ibn al-Arabi's doctrine of the unity of being. He died in 736/1336 and was buried in the Ahrar burial ground in his native Sufiabad.