King Pilliya of Kizzuwatna had to sign a treaty with Idrimi. Kizzuwatna became an ally of Mitanni from the reign of Shunashura I to that of Hittite King Arnuwanda I, who overran the country and made it a vassal kingdom. The exceedingly rough and unfavourable terrain of the Tarsus Mountains made it likely that to remain in a position of prominence among their Hurrian- and Luwian- speaking neighbours, the Kizzuwanta requested favourable terms and that they were subsequently granted.