We travel to Dar es Salaam in Tanzania - a country that many believe can teach a lesson to others seeking unity and stability, because right from the start the first post-independence leader Julius Nyerere insisted that everyone should learn Swahili. Well over a 100 other languages are still spoken in Tanzania but many people believe that Nyerere – partly because of his language policy - was a successful nation builder. Join Owen Bennett Jones and his guests as they discuss language and politics in Tanzania. (Photo: School children sitting in a classroom. Credit: Getty Images)