The Kush Empire ruled from 1070 B.C. to around 350 A.D. in what is now known as the Republic of Sudan [source: Welsby]. Over the course of its long history, not much is known about the exact details of its politics; however, there is evidence of monarchies during the later years. Still, the Kush exerted power over several smaller nations in the area and managed to maintain power in the region while expanding south to conquer lands with a resource they relied on, timber. Its economy was heavily dependent on trading iron and gold.
Some evidence suggests the empire came under attack from desert tribes, but other scholars speculate the territory's overdependence on the iron economy lead to deforestation, forcing its people to disperse when they ran out of timber needed to burn to forge the iron. [source: BBC].
Other empires failed because they exploited their own people or neighboring countries, but the deforestation theory suggests the Kingdom of Kush fell because it destroyed its own land. Its rise and its fall were connected to the same industry.