For their participation, the levies against the Harri had been lifted, and the enlarged army crossed the Euphrates and into the lands of the Mitanni in a grand scale attack, first entering and overtaking Ishuwa, a prized area previously eyed by his predecessor, Hattushil. But the Hattic army did not stop there, moving next into Alshe, the adjacent province, and soon threatened encroachment upon the heart of the Mitanni kingdom.
King Tushratta of the Mitanni, tied directly to the Egyptian throne by marriage (brother-in-law to Amenhotep III) raised his banners and set to meet Shubbiluliuma's invaders in the field. In response, the king of Carchemish (unnamed thus far by historic record) of Syria, joined his forces to the invading Shubbiluliuma's, gaining favor above his fellow princes. Records do show however that Carchemish in the many years to follow would have direct Hittite bloodlines, hinting that this Syrian city-state did indeed become the favored nation amongst the Hattic king's new allies.
Reenforced by both auxiliary armies of the Harri and now the soldiers of Carchemish, the inevitable drumbeat began to sound as the Hattic forces neared their first massive battle with the Mitanni, led by Tushratta. The call by the defending forces' king beckoned that every last man must ride or die, their freedoms to perish along with any resulting failure. Their security threatened, both proud leaders set their sights upon the dawn in a prelude of their inevitable confrontation.