The longest war in Yoruba land lasted _____ years.

The longest war in Yoruba land lasted 16 years. The Yoruba people are an ethnic group native to Nigeria, and their history is marked by periods of inter-city conflict and warfare. The longest of these wars was fought between the city-states of Ife and Modakeke and lasted for 16 years. The conflict was sparked by disputes over land and resources, and it involved several battles and skirmishes before it was finally resolved through negotiations and the intervention of outside mediators. Today, the Yoruba people have largely put aside their differences and come together as a unified cultural group, with a shared history and rich traditions.