A younger son of the Hittite great king Tudḫaliya IV, Šuppiluliuma II succeeded his elder brother, Arnuwanda III, on the throne in c. 1207 BC.

[1] The new king exacted oaths of allegiance from his court and subjects, advertising his loyalty to his deceased older brother and his own legitimacy in the absence of any heirs of his predecessor.

Without providing specifics, the surviving texts suggest a context of disloyalty and potential challenges to the throne by members of the extended royal family.

[9] Reasserting Hittite central control over southern Anatolia and its coasts might have been more than a matter of pride, as suggested by references to urgent grain shipments from Merneptah, the king of Egypt, and from Mukiš in northern Syria.

[10] Following an earlier invasion of Alašiya (Cyprus) during the reign of his father, a fleet under the command of Šuppiluliuma II defeated either the Cypriots or a group of the so-called Sea Peoples who had established themselves on the island, the first recorded naval battle in history.

[13][14] The Sea Peoples had already begun their advance along the Mediterranean coastline, apparently starting from the Aegean, and continuing all the way to Canaan, some of them settling in Philistia and at Dor.

Šuppiluliuma II was probably the ruler who abandoned the capital city of Hattusa,[17][18] possibly contributing to the fall or disappearance of the Hittite kingdom.

Some scholars indicate that Šuppiluliuma II's end is unknown or that he simply "vanished",[14] while some claim he was killed during the sack of Hattusa in 1190 BC.

The reasons for this are unclear and might have combined various natural phenomena (including droughts and earthquakes) with internal and external strife or political and military pressures.