evidence: Researchers later discovered walls about 6,000 to 13,000 kilometres long that were apparently erected to mark territories. The capital city was rebuilt, and between 1440-1470 Oba Ewuare turned the Benin empire into a fortress protected by walls and moats, and that was from where he launched his military exploits and expanded the kingdom. Places like Idah, Akure, Owo all fell under his authority. At the height of its power, the Empire is said to have amassed territories beginning from present-day Onitsha in Nigeria through southwestern Nigeria all the way to the coastline of Ghana.