Slavery has existed in Africa for as long as recorded history. Ancient Egypt had slaves toiling away in its fields and on its monuments, ancient Carthage trafficked in slaves across the Mediterranean, and the Ethiopian kings of Aksum wrote proudly of the slaves they took in war. Slaves were also exported from Africa for centuries before Europeans arrived. The Trans-Saharan slave trade lasted for over a thousand years and dragged about 10 million people across the desert to be slaves in the Islamic world. The Indian Ocean also had a similarly long-lasting ocean-going slave trade with about 5 million ending up in slave ships, bound and branded for use in foreign lands. These slaves ended up as labourers, domestic servants, soldiers, or more. Male slaves in the Islamic world were typically castrated which meant that new slaves had to be regularly imported to maintain the population.