Picture to yourself, a rocky humid land, with small villages and impressive fortified sandstone cities. An unnavigable river streams as far as an eye could see.
A great fortified city stands on that river; and behind its mound, there is an army.
Two scouts returned to their king, who was with that army. They brought good news; the enemy fell for their trap. They tricked them, and managed to escape. The king is furious; his subjects are thinking of their hides rather then of HIS greatness! Their escape might hint the enemy off!
Charioteers! Quickly, to battle! Before the Egyptians realize what happened, we must strike!
History will never be the same again...
---
It is the 13th century BC, in Syria. Syria is still divided into city states, weak ones, that traditionally were a battlefield between three empires...
To the north, the Land of Hatti, the land of great warriors, who are made particularily interesting by the fact that they spoke a "Nesite" langauge. Though in the past, Great Kings of Hatti shared their power with an elective "pankus", this tradition gradually ceased to be. Now, the kings ruled supreme.
To the south, Egypt, a land that scarcely needs any introduction, a land of the Pharaohs... and their slaves. Arrogant, Egyptians nonetheless have good reasons for it; for none is a state that is stronger then Egypt. So far.
To the east, Mitanni, a great Mesopatamian empire, and a one that was for long the ruler of Syria. It was gradually pushed back, but the Mitanni remained a significant regional power until...
...1360, when the Mitanni united Egypt and Hatti against themselves. In a series of battles, the Mitanni were crushed; Hittites sacked the capital, Wassukkani, and dynastic strife ensued with the death of the last Mitanni king. Eventually, Hittites fully took over Mitanni; this wasn't a long-term conquest, as eventually most of Mitanni lands were lost to the Assyrians, but the Hittittes didn't want them all that much. They gained what they did want - hegemony in Northern Syria.
Thus now, with Mitanni gone, it was Hatti vs. Egypt, one on one. However, without allies, neither side seemed to be stronger then the other, so stalemate ensued in Syria. Both sides incited rebels against each other, Egyptians tried to win Assyrians over to their side... but the situation remained unconclusive.
Then, a new, energetic dynasty rose to power in Egypt - the 19th dynasty. Ramses I didn't reign long, but his son Seti did, and he started campaigns into Syria, fighting Muwatallis of Hatti; the results, again, were rather inconclusive, but the order was temporarily settled on the Orontes river.
Orontes river, on whose side stood the city of Kadesh, the city that constantly switched hands. Independant, Mitanni, Hittite, Egyptian, Hittite again... It was only natural that one of the greatest battles of the ancient world, between Muwatallis' Hittites and Ramses II's Egyptians should take place at that city, in 1275 BC.
The Hittites used classical disinformation; they had "defectors" inform Ramses II that the Hittites were amassing at Aleppo, whilst they really were at Kadesh. Elated, the Pharaoh hurried to besiege Kadesh before the Hittites come. Just before the battle, the "defectors" - really Hittite spies - separated from the army and made way for Kadesh; by the time the Egyptians noticed their absence, it was too late. Re and Amon divisions were routed; Muwatallis, nervous before the battle, encouraged his forces to finish off the Egyptians before plundering, and Ramses, surrounded, was cut down. Hitittes won a crushing victory; they followed it up by defeating the Egyptian Canaanite mercenaries that came too late and by plunging headfirst towards Meggido.
What ensued in Egypt could only be described as chaos. Khaemweset I rose to power, but it was a very shaky rule, for the southern provinces rose in arms, and so did all of the Asian holdings. Libyans raided as far as Pi-Ramesse. And the Hittites exploited all this chaos well. The desert chieftains in all of Egyptian Asian holdings were only too happy to join them; the cities, such as Byblos, were not as enthusiastic about it, but upon a guarantee of their comparative autonomy, they were swayed as well. Hittite factual control was now extended as far as Gallilea; and further south, vassal states arose. Muwatallis was allegedly planning a conquest of Egypt itself when he suddenly died, to be succeeded by Mursilis III. Mursilis proved a weak ruler, and civil disorder under his rule allowed Egypt to recover. Nonetheless, the Hittites managed to fight off Assyrians in the east whilst the western border was quite "calm" - that is to say, Lycians and Thracian-Phrygian tribes had better things to do, fighting on the Trojan side in the ongoing Trojan War; Lycians in particular distinguished themselves, saving Troy from certain destruction at Greek hands (actual reasons for the draw in the Trojan War are butterfly effect plus the generally-weaker state of Greece caused by more long-term disruption of Levantine trade and by the stronger Hittites forcing would-be Phrygian Thracians to concentrate more on fighting Greeks; that said, one might also note that if we assume the "Ahhiyawans" mentioned in Hittite texts are indeed Achaens, a stronger Hittite Empire is liable to assist Trojans against this state that is perceived as strong and potentially-hostile).
Eventually, the Hittites gained another great leader - in 1252, Telepinus II the Great rose to power. By then, Khaemwese managed to restore some semblance of order in Egypt; but it was not enough to become a threat to the Hittites yet. Indeed, Telepinus cast his eyes in a different direction - to the east. Ever since the Mitanni fell, Hanigalbat, the Hittite province there, fell under Assyrian control, but eventually regained independance and begun regaining power. The Hittites traditionally encouraged this; they found a buffer state against Assyria useful. But the Assyrians were still firmly on the rise, and they felt that Hanigalbat was theirs by right. An opportunity appeared when Shalmaneser, whilst campaigning in Urartu, was sneak-attacked by Hanigalbatians, who cut him off from water supplies. His Assyrians managed to fight their way out of this predicament, though, and soon carried the war to Hanigalbat. Hittites were at first taken by surprise as Hanigalbat was crushed and subdued; then again, perhaps Telepinus wanted Hanigalbat out of the way just as well. Persuading the Babylonians that Shalmaneser was a grave threat, the Hittites soon entered the war, defeating the Assyrians at Harran; Shalmaneser tried to fight on, but he was pushed back on both "fronts", and eventually Assyria was partitioned between the victorious powers. That was in 1249. But soon, problems about how it should be divided arose, and Telepinus now started a war with Babylon. Babylonians at that time were also preoccupied with the Elamites, so they proved easier prey for the great Hittite hordes. In 1247, Hittites had conquered Babylon yet again; Elamites, meanwhile, extended their rule as far west as Ur.
It is unclear whether Telepinus intended to attack Elam as well, as the Egyptians soon gained his attention. Whilst he was in the east, they incited a major Canaanite rebellion; however, one of the conspirators, a Hebrew chieftain, gave up the secret of the rebellion to Telepinus; Hebrews still had a grudge with Egypt, and with the other Canaanites too. So Telepinus did manage to despatch a small army to defeat the rebellion whilst he was preoccupied; but it was not enough, for Egyptians decided to send their own army in as well. Hittites were defeated at Gaza, and so Telepinus had to put any more Mesopatamian ambitions on hold. Instead, he pursued war with Egypt. Egyptians since then managed to reform their army, adopting the Hittite three-man chariot. In a close-ran battle at Har Megiddo, however, the Egyptians still were defeated, and Telepinus pressed forward into Egypt. Khaemwese organized a defiant resistance, but it was no use, and by 1240 Egypt, apart from the breakaway southern provinces, was subdued. Telepinus now ruled the largest Hittite Empire ever; it was most unfortunate that he died soon after.
No, the Hittite Empire didn't fall apart immediately, though it was weakened by the rebellions and lost several periphereal holdings, especially in western Anatolia. The Empire held on to life until 1228, when Telepinus III passed away. Egypt and Assyria quickly regained independance; Phrygians captured a northwestern chunk of Anatolia; and all this scarcely mattered, for soon the entire map of the western Middle East was to be rewritten. Rewritten by the Sea Peoples.