Simplify the following text for a Grade 9 native English-speaking person.
Original: 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 .
Simplified: 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 .