In his Kitab al-masalik wa 'l-'mamalik (Book of Routes and Realms, 1068) the Spanish Muslim geographer al-Bakri included a traveler's account of how the people of the Empire of Ghana buried a deceased ruler :

When the king dies, they build over the place where his tomb will be an anormous dome of wood. They bring him in on a bed... At his side they place his ornaments, his weapons and the vessels from which he used to eat and drink. They also place there the man who had served his meals. They close the door of the dome and cover it with mats and materials and then they assemble the people, who heap earth upon it until it becomes like large mound.

Source: Margaret Shinnie, Ancient African Kingdom (London: Arnold, 1965), p. 49