The Desturi za WaSwahili (Customs of the Swahili People) ranks among the world's great but little-known literary achievements. It records something of the life and traditions of a numerically small people, of a culture that has grown up over centuries to give birth to its own literature, philosophy of life, and values. Too many such civilizations – each a unique and irreplaceable gem of human achievement – have disappeared without a trace. Some have left a few place names, a few genes and games, a fell disease or two, while others are brought to mind only by the descriptions of outsiders. Some have managed to survive to the present, be it by sheer refusal to die, by military prowess or non-violent forms of resistance, or by the protection of the unhospitable nature of a xenophobic terrain. In the case of the Swahili we have a people few in number, inhabiting an open land that has no natural borders or defences, who have gone serenely and happily on, while their invaders – various waves of outsider Africans, Arabs, Iranians, Portuguese, Germans, and British – have disappeared, leaving behind their trace in ruins littering the countryside and in vestiges embedded in the Swahili language and culture.