Question

What led to the divide of the Roman empire

Answer 1

If you are referring to the 3rd century the thing that led to the divide in the Roman Empire was a high populas. Because the population was growing so much it was decided that Rome would be split up with each part of it being governed by a different leader

Answer 2

The Roman Empire had become too large to be ruled by one emperor by the third century (this was one of the causes of the Crisis of the Third Century). It was divided, by Emperor Diocletian, into a tetrarchy. This tetrarchy was then dissolved in favor of an Eastern and Western Roman Empire.