Disintegration
After Abu Sa'id's death in 1335, the khanate began to disintegrate rapidly, and split up into several rival successor states, most prominently the Jalayirids. Hasar's descendant Togha Temür, who was the last of the obscure Ilkhan pretenders, was assassinated by Sarbadars in 1353. Timur later carved a state from the Jalayirids, ostensibly to restore the old khanate. The historian Rashid-al-Din Hamadani wrote a universal history for the khans around 1315 which provides much material for their history.
Read more about this topic: Ilkhanate