 He had been informed beforehand about the assassination plot, and afterwards protected Shams al-Din 'Ali's murderer, Haidar Qassib.Unlike his predecessor, Yahya was a religious moderate and did not maintain many of Shams al-Din Ali's social programs.Early in his reign, Yahya undertook negotiations with the Ilkhanid claimant Togha Temur, who ruled in Astarabad.