Very early in Ramses II's reign, probably still co-regent of his father, he went on his first military campaign to put down a rebellion in Nubia. Reliefs in a small rock temple at Beit el-Wali commemorating the event show the young King in the company of two of his children (the Crown Prince Amunherwenememf, and Khaemwaset) standing proudly in their chariots.
In the 14th year of his regency, Ramses II led his first major campaign to Syria, which resulted in that Amuru returned to the Egyptian hold. This was not to last long, for the Hittite King, Muwatalli, decided at once to reconquer Armuru and to try to prevent further losses of territory to the Egyptians, with the result that the following year Ramses II again passed the border fortress at Sile, to declare war directly against his rival. The battle of Kadesh which followed is one of the most famous armed conflicts of antiquity. In that battle, Ramses, despite the fact that he was unable to achieve his goals, presented it at home as a huge victory described at large in lengthy compositions which were carved on the walls of all the major temples.
Many of Ramses' high officials lived and worked in Piramesse, but most of them appear to have been buried elsewhere, particularly in the necropolis of Memphis. About 35 tombs of the Ramesside Period have so far been excavated there, some of them very large. These tombs still have the form of an Egyptian temple, but compared to the tombs of the late Eighteenth Dynasty, the workmanship had declined.
Ramses II was the first king since Amenhotep III to celebrate more than one Sed-Festival. The first took place in the 30th year and then another thirteen followed, at first at more or less regular intervals of about 3 years, and then towards the end of his long life, annually. Amenhotep III had become deified during his three jubilees, but in this respect Ramses II had less patience than his great predecessor, for already by the 8th year of his regency, we hear of a colossal statue being carved which was given the name 'Ramses-the-god'. Inside the temples, Ramses-the-god had his own cult-image and processional bark along with the other deities to whom they were dedicated. In reliefs, Ramses II is often shown offering to his own deified self.
Among the King's many sons who held high positions, the second son of Queen Isetnefret, Khaemwaset, was High Priest of Ptah in Memphis and acquired a reputation as a scholar and magician that survived until Roman times. As a high priest of Ptah, one of his duties was to participate in the burial of the sacred Apis-Bull and it is to Khaemwaset that the first galleries of the Serapeum are due. By the 52nd year of his father's regency, Khaemwaset was the eldest surviving son and therefore became crown prince, but at that stage he must have been in his sixties already, and he died a few years later, aging around 55. He was almost certainly buried in the Memphite necropolis and not in the princely gallery tomb in the Valley of the Kings (KV 5), but whether he was really interred in the Serapeum, as many believe, is less certain.
After Khaemwaset's death, Ramses II lived on for another 12 years until he finally died in the 67th year of his regency, the longest reigning monarch since Pepy II of the Sixth Dynasty. During the last years of his reign, he had become a living legend and he was clearly much admired by his successors. He survived his 12 eldest sons and it was Merenptah (the fourth son of Isetnefret and crown prince since the death of Khaemwaset) who eventually succeeded him.