The political environment which resulted from this revolt would lead the next Ottoman Sultan, Selim I, to take violent measures against the Qizilbash and declare war on Iran. Counted among these violent measures was the decree from Selim I to kill more than 40,000 Qizilbash, children and elderly included, in Rumelia and Anatolia prior to the Battle of Chaldiran in March 1514. In undated letters from Selim I sent to Isma'il I, estimated to have been written in 1514, Selim I wrote that "it has been heard repeatedly that you have subjected the upright community of Muhammad to your devious will" and expounded upon his plans to "crown the head of every gallows tree with a crown-wearing Sufi and clear the faction from the face of the earth".