Before the British arrived, the Kikuyu had developed one of the most sophisticated agricultural systems in East Africa. They farmed the ridges between rivers, rotating crops across carefully managed plots. Sweet potatoes, yams, maize, beans, and bananas were grown in layered combinations that maximized yield and maintained soil health. Land was held collectively under the githaka system, managed by lineage groups. Farmers knew which soils suited which crops, when to plant, when to leave land fallow. When the settlers seized the highlands, they did not take empty land. They took a working agricultural economy.