The son of Tudhaliyas III, Suppiluliumas became king of the *Hittites in 1380 BC, and his reign introduced a new era of expansion and military power.
He conducted a brilliant campaign, overthrowing the rival kingdom of *Mitanni in 1370 BC, and eventually brought the whole of northern Syria as far as Kadesh under *Hittite control. It is possible that he would have held the *Hittite boundary as the River Orontes, but the ruler of Kadesh (who was an Egyptian vassal) entered into battle with the *Hittites and was defeated, so that Suppiluliumas' army went as far as Abina near Damascus. The *Hittite king was recalled by problems at home, but he returned to campaign in Syria in 1340 BC.
Suppiluliumas' progress in the area was made easier because *Akhenaten (to whom Suppiluliumas had sent a letter of congratulation on his accession) was preoccupied with his religious reforms in Egypt. Towards the end of *Akhenaten's reign, the kingdom of Amurru in central Syria had been forced into an alliance with the *Hittites and thus Egypt had lost another province; gradually, the *Hittites undermined Egypt's empire throughout Syria/Palestine.
Against this background of hostility and mistrust, it is therefore even more surprising to discover that an Egyptian queen (almost certainly *Ankhesenpaaten/ Ankhesenamun) wrote to the *Hittite king, Suppiluliumas, beseeching him to send a prince to marry her. Suppiluliumas was obviously wary of this request, and sent an envoy to Egypt to investigate further. The envoy returned with a reiteration of the queen's plea, and Suppiluliumas eventually sent a son to Egypt, but he was murdered on arrival, probably by the agents of the rival faction in Egypt who did not wish to see their country handed over to their arch-enemy through the agency of a royal marriage.
This murder of a *Hittite prince had repercussions; there was immediate retaliation by Suppiluliumas who sent his armies against Egypt's Syrian vassals and, in the longer term, there was a period of distrust and warfare between Egypt and the *Hittites. Suppiluliumas died of a pestilence only a few years after his ill-fated son.
BIBL. Kitchen, K.A. Suppiluliumas and the Amarna Pharaohs. Liverpool: 1962.
Biographical Dictionary of Ancient Egypt by Rosalie and Antony E. David
Ancient Egypt. A Reference Guide. EdwART. 2011.