Why the first cities hugged rivers
Farmers settle where the Nile or Tigris floods and leaves rich soil, food piles up, and a village swells into a city with rulers and writing. Early civilizations grew beside rivers because water meant crops, and crops meant people could stop wandering.
Cradles by the rivers
The first cities grew in fertile river valleys — Mesopotamia between the Tigris and Euphrates, and Egypt along the Nile. Reliable water meant surplus food, which freed people for trade, writing, and government.
Surplus → specialization
When farmers grow more food than they need, others can become builders, priests, or scribes.