The Swahili civilization dates back to at least the fourteenth and fifteenth centuries. When the Europeans visited the coast in the nineteenth century, Swahili towns appeared to be products of a Persian and Arab Diaspora that had spread around the Indian Ocean. There were extensive and elaborate buildings and a large scale of imports of Islamic and Chinese pottery. These lasted until the Portuguese destroyed a number of towns during the sixteenth century in their attempt to control the Indian Ocean trade routes. This is one of the main causes for the decline of the coastal habitat of the Swahili people, a clear evidence being the towns of Kilwa and Mafia on the coast of Tanzania.
Scholars claim that Swahili is a combination of a number of languages.
Some have even claimed that Swahili has Arabic origin. While the term Swahili has its origin from Arabic, Sahel or Sawahel, which means coast, the language of the people, and which is referred to by the speakers as Kiswahili, has characteristics of Bantu languages. Not only has Swahili borrowed heavily from Arabic but also from many European languages. The basic sound system and grammar is closely related to Bantu languages of northeast Tanzania, Kenya, and the Comoro Islands. Swahili is the lingua franca of Tanzania and Kenya.