Ata-Malik Juvayni
Ruknuddin Hasan (Rukn al-Dīn), surnamed Khurshāh or Khwarshāh was born in 627 AH/1230 CE. He is also known as Kahirshah. When he was still a child, his father had declared him as his successor. Persian historian Ata-Malik Juvayni tried to adulterate the Nizari line of Imamate, but at one place he curiously writes (p. 663), "And today, the leader (Ruknuddin Khurshah) of the heretics (the misnomer used for the Ismailis) of Alamut traces his descent from this son (of Nizar)."