The Incas expanded very rapidly and soon became an empire. They had a system they used each time they conquered another tribe or when a tribe voluntarily joined the Inca Empire. Three things happened at the same time very quickly.
1. Roads were built to connect the new province to the rest of the empire.
2. A count was made of every item in the conquered territory. Government officials, accompanied by the military, would enter the conquered territory and count all the wealth - every vase, every llama, every person.
3. A governor was appointed to run the new territory.
Some of the military remained to keep order. Some of the military left, bringing much of the conquered tribe with them. Those people would be scattered throughout the Inca empire. That forced the new people to learn the Incan language. The Incas gave them some time to settle in. If they did not settle in and do the job they were assigned in a reasonable amount of time, they were killed. The Inca did not tolerate rebellion, no matter how small the act.
All the new people had to speak the Inca language. They had to worship Inca gods. They had to follow Inca ways
The new people were given one freedom. They could additionally worship gods of their own, if they wished, and follow their religious customs. However, this could not interfere with their work, or it had to cease immediately.
It was an effective way of handling a rapidly expanding and briefly diverse population. In no time, the new territory was absorbed into the Inca Empire. The empire continued to have a common language, a common government, and huge storages of food and goods available for use in times of need for all the people in the Inca Empire.