The wars are over. Unfortunate, as the Gods will not be receiving quite as many sacrifices. Moctezuma must now place a limit on his ambitions, especially as he grows into old age. Between slave raids against the savage tribes, and tribute from the conquered lands, the Gods will remain satiated. The Empire will grow, but first it must recover. Moctezuma's great campaigns have severely drained Tenochtitlan. The great Chief still commands the fear and loyalty of the tribes, but if he dies, his successor might not be able to hold the new Empire together. For now the Chief must simply wait, and allow his people to recover.
The Mayans are no longer as despised as they were, having been rendered impotent by Moctezuma. The Guatemala Mayans offer immediate loyalty, more than can be said of even some Aztlan tribes. They are given privileges and lowered tribute, in exchange for troops and complete obedience to the Chief.
Under Moctezuma's divinely inspired guidance, the Priesthood and the Aristocracy maintain a tight thumb over Tenochtitlan. Some of the tribes further from the capital still maintain traditional tribal freedoms, but only because they are too insignificant to bother with. The social status quo is maintained, at the cost of progress and initiative amongst the masses.
Rebellions still break out from time to time. Eventually this sort of activity will cease, which is a mixed blessing. These rebels keep Moctezuma on his toes, and provide ample sacrifices for the Gods. A particularly large rebellion breaks out in Mixtec. The Sun-Emperor, as Moctezuma is now styling himself, crushes it with ease, and reaffirms his dominance over the tribes. He is well into his old age though, almost ancient by the standards of mortal men. Despite his great strength, he will eventually die. Then it will be up to his son to ascend the Emperor's lofty throne.
Even as the Sun-Emperor nears death, further strides are being made in the integration of the tribes. Although he is willing to crush rebellions, Moctezuma wishes to avoid large scale tribal war, lest his son find himself empty handed when inevitable civil war breaks out. Therefore, the integration is purely diplomatic, although a satisfyingly large tribute of sacrificial victims is exacted.
These puny blasphemers will feed the Sun God, sooner or later!
Probably later.
The conquests of Moctezuma were a turning point. Such a man could only have been placed on Earth by the Gods. The events surrounding his life will have severe consequences. Change is perhaps inevitable, but an unspoken consensus has been reached amongst the people. Traditions are a fine thing. Although the status quo will inevitably shift, change for change's sake is pointless inanity. This widespread philosophy is approved of, and a hundred hearts are offered up to Quetzalcoatl, in thanks for this depth of thought.
A few years of peace yield ample results. The Sun-Emperor's armies are once again fit to make war. It is unfortunate that the Empire will soon make war on itself, but such is the way of things. It will feed the Gods regardless.
And of course, as is also the way of things, the Sun-Emperor passes. Soon he will become a legend, the great founding hero of a mighty Empire, or perhaps some distant champion of a long extinct tribe. His son, Axayacatl is cunning and strong, but he is also somewhat incompetent, and he is almost universally despised amongst the conquered tribes for his many excesses as heir. As Moctezuma expected, an enormous civil war breaks out, threatening to tear the fledgling Empire apart.
Fortunately, although Axayacatl is hardly suited to ruling an Empire, he can certainly fight his way to the throne. He is not the man his father was, but his skills as a commander are still formidable.
Despite all this, the situation is dire. Internal tensions have suddenly exploded into a maelstrom of violence. It is clear that many of these tribes cannot be trusted. If the war is one, they must be destroyed, or at least kept on a tight leash.
Axayacatl certainly does not enjoy popular support either. In the eyes of the conquered, he has wronged them as much as his father, but he lacks that great strength of mind that lead Moctezume to conquer the world.
The standing army is split up into three forces, the Tenochtitlan guard, and two other smaller garrison armies dedicated to preventing rebellion. The army in Pokomom is thrust out by rebellious tribes, but not before losing many hundreds of good soldiers.
Further north, Axayacatl manages to win himself a victory, but it is hardly significant. Anything other than a complete rout will only delay the rebels. If this continues, many thousands more will join the ranks of the traitors.
The Pokomom force retreats to Guatemala, a still loyal region, to reinforce. Meanwhile, Axayacatl consolidates his forces in the North, and wins several victories against the rebels. It would seem that the civil war will come down to Pokomom. The rebels are slowly retreating there, so they must be routed there.
Axayacatl is forced to deal with some rebels far to the North, for fear of losing Tenochtitlan. This detour allows the rebels to capture Pokomom and subdue any remaining loyalist tribes. Axayacatl is heading Southeast with a full 9000 men, this will be settled in the lands of the Zapotecs.
The rebel victory in Pokomom causes a complete collapse of Moctezuma's carefully constructed tribal loyalties. This will take years to remedy, but that is not an immediate concern.
Axayacatl links up with his men in Guatemala, leaving his main force under the command of a trusted old nobleman. The majority of rebels have moved West, leaving only a small force barely over 4000 men to guard Pokomom. Axayacatl is confident that he can win. With Pokomom under siege, the rebels will be isolated and surrounded.
The battle is won (Didn't get the picture, blame either Fraps or my own incompetence) allowing Axayacatl to link back up with his main army. A subsequent triumph is obtained over the traitors. They are chased back to Pokomom and scattered. The war is won, the Gods will feast.
Pokomom is retaken, and all trace of the rebel scum is purged from the Empire.
Axayacatl finally takes the reins of government. He is found to be wanting, but not severely so. He is widely despised, but he has proven himself to be more than just his Father's heir. The tribes will think twice before crossing the new ruler of Tenochtitlan.
Sacrificial rituals are held throughout the Empire, and of course the most grand occur in Tenochtitlan itself. Hundreds of prisoners are sacrificed in a late coronation ceremony. The High Priest of the city crowns Axayacatl as Sun-Emperor of Aztlan with one hand. In his other, he clutches the still beating heart of a prominent rebel leader. Praise be to Huitzilopotchli!