After the extreme long reign of his father Ramses II, all of his elder brothers predeceased him, and he must have been in his fifties, when he ascended the thrown. He was the third son of Ramses II and the Great Royal wife Isis-nefert. He married his full sister also called Isis-nefert and probably married also Takhat. With Isis-nefert he got 2 sons, Seti-Mery-n-Ptah and Amenmesse
A third marriage was that of Mery-n-Ptah and Bintanta, former Great Royal wife and daughter of his father Ramses II.
He undertook many campaigns in these troubled times against the Nubian’s and Libyans. Accordingly to Manetho he reigned 15 years, but the last record dates from year 9. 3 months.
The mummy was discovered among those in the cache KV35.