In Children of Hope, Sandra Rowoldt Shell details the life histories of sixty-four Oromo children who were enslaved in Ethiopia in the late nineteenth century, liberated by the British navy, and ultimately sent to a Free Church of Scotland mission in South Africa, where their stories were recorded through a series of interviews.
One of them was Bisho Jarso, a great educator, who taught a father of Thabo Mbeki , the second president of South Africa. Bisho's grand son Neville Edward Alexander was the first of six children of Dimbiti Bisho Alexander was a friend of Mandela and in prison with Madiba for 12 years.
He was an instrument for successful South African Language policy. You can get their story in this book.