We know precious little about the Kanem Empire and how its people lived -- most of our knowledge comes from a text discovered in 1851 called the Girgam [source: Clark]. Over time, its primary religion became Islam, however it's thought the introduction of the religion may have brought internal strife in the empire's early years. The Kanem Empire was established sometime around 700 and lasted until 1376. It was located in what is now Chad, Libya and part of Niger.
According to the text, the Zaghawa people first founded their capital in 700 as the city of N'jimi. The empire's history is split between two different dynasties, the Duguwa and the Sayfawa -- the latter being the driving force to bring Islam to the country. Its expansion continued, including a period in which the king declared a holy war or jihad against all surrounding tribes.
The military system devised to facilitate the jihad created a governmental system based on hereditary nobility, in which soldiers were rewarded with the land they conquered, which they passed down to their sons. That system resulted in civil war that weakened the territory and made it vulnerable to attack. Bulala invaders were able to quickly take N'jimi in 1376 and eventually take control of the entire Kanem Empire.
The lesson of the Kanem Empire is that unpopular decisions can create internal conflict, leaving a once powerful people defenseless [source: Goodwin]. It's a story repeated throughout history.