The genesis of Swahili language
A common saying, that Swahili was born in Zanzibar, grew up in Tanzania, fell sick in Kenya, died in Uganda and was buried in Congo, probably gives a lighthearted image of the twists and turns that arguably the most widely spoken language in Africa has taken since it was born out of interaction between the coastal Bantu peoples of East Africa and the Asians.
A map showing places where Swahili is spoken.