Why did empires start in the Fertile Crescent?

Answer 1

There are two main reasons for this.

1) Early Civilization: The Fertile Crescent, specifically Mesopotamia, was one of the earliest places where settlement began. The presence of the Tigris and Euphrates Rivers provided the substantial amounts of water needed to grow crops. Incidentally, several important grains such as barley, wheat, spelt, and bulghur and several important forms of livestock such as cows/oxen, sheep, goats, and horses were in the Middle East. This made it a very productive area early on.

2) Topographical Flatness: Central and southern Mesopotamia is more or less flat-land with very few forests or overgrowth. This makes it very easy for an army to easily see defensive positions and overtake them. By contrast, hills, mountains, and forests are good defensive terrain which can be used to stall or counter-attack an imposing army. It is no accident that most societies in mountainous or densely wooded areas are those who escaped the grasp of major civilizations until the modern era.