Although Rameses boasted on his return home of having achieved a great victory, there is nothing more certain than that this campaign proved a dismal failure. He was unable to win back for Egypt the northern territories which had acknowledged the suzerainty of Egypt during the Eighteenth Dynasty. Subsequently he was kept fully engaged in maintaining his prestige in northern Palestine and the vicinity of Phoenicia. Then his Asiatic military operations, which extended altogether over a period of about twenty years, were brought to a close in a dramatic and unexpected manner. The Hittite king Mutallu had died in battle, or by the hand of an assassin, and was succeeded by his brother Hattusil II (Khetasar), who sealed a treaty of peace with the great Rameses. An Egyptian copy of this interesting document can still be read on the walls of a Theban temple, but it is lacking in certain details which interest present-day historians. No reference, for instance, is made to the boundaries of the Egyptian Empire in Syria, so that it is impossible to estimate the degree of success which attended the campaigns of Rameses. An interesting light, however, is thrown on the purport of the treaty by a tablet letter which has been discovered by Professor Hugo Winckler at Boghaz Köi. It is a copy of a communication addressed by Hattusil II to the King of Babylonia, who had made an enquiry regarding it. "I will inform my brother," wrote the Hittite monarch; "the King of Egypt and I have made an alliance, and made ourselves brothers. Brothers we are and will [unite against] a common foe, and with friends in common."[411] The common foe could have been no other than Assyria, and the Hittite king's letter appears to convey a hint to Kadashman-turgu of Babylon that he should make common cause with Rameses II and Hattusil. Shalmaneser I of Assyria was pursuing a determined policy of western and northern expansion. He struck boldly at the eastern Hittite States and conquered Malatia, where he secured great treasure for the god Ashur. He even founded colonies within the Hittite sphere of influence on the borders of Armenia. Shalmaneser's second campaign was conducted against the portion of ancient Mitanni which was under Hittite control. The vassal king, Sattuari, apparently a descendant of Tushratta's, endeavoured to resist the Assyrians with the aid of Hittites and Aramaeans, but his army of allies was put to flight. The victorious Shalmaneser was afterwards able to penetrate as far westward as Carchemish on the Euphrates. Having thus secured the whole of Mitanni, the Assyrian conqueror attacked the Aramaean hordes which were keeping the territory round Haran in a continuous state of unrest, and forced them to recognize him as their overlord.