It is the Strait of Gibraltar. It is around 9 miles wide at its tightest point, the Strait of Gibraltar is the passage point into the Mediterranean Sea from the Atlantic Ocean. It is circumscribed by the landmasses of Africa and Europe, and the nations of Morocco, Spain, the British province of Gibraltar, and the Spanish exclave of Ceuta
The three main groups probably have been the British, the Boers and the Zulus
It left the entire west in ruins, basically the reason for feudalism and the Dark Age