Suppiluliuma II , the son of Tudhaliya IV , was the last known king of the New Kingdom of the Hittite Empire , ruling 1207 BCE -- c. 1178 BCE , contemporary with Tukulti-Ninurta I of Assyira . Suppiluliuma II , the son of Tudhaliya IV , was the last known king of the New Kingdom of the Hittite Empire , ruling ca . 1207 â `` 1178 BC ( short chronology ) , contemporary with Tukulti-Ninurta I of Assyria .