What happened
In c. 1274 BC — year 5 of Ramesses II — the Egyptian and Hittite armies clashed at Kadesh on the Orontes. Misled by false intelligence from captured scouts, Ramesses advanced with only part of his army and was ambushed by massed Hittite chariots. Per the Egyptian accounts, the king personally rallied his troops until reinforcements arrived. The battle is often described as the largest chariot battle ever fought, with thousands of chariots engaged, though estimates vary.
Background
Egypt and the Hittites had long been rivals over control of Syria and its trade routes. Kadesh was a key point in that contest.
Consequences
The battle was tactically inconclusive: both sides claimed victory, and Kadesh stayed in the Hittite sphere. C. 1259 BC, Egypt and the Hittites concluded one of the earliest surviving written peace treaties between great powers. Copies survive on Egyptian temple walls and on cuneiform tablets from the Hittite capital Hattusa, and a replica is displayed at the United Nations headquarters.