Complex sentence: Sahle Maryam was handed over to the Emperor, taken to Gondar, and there trained in Tewodros's service, and then placed in comfortable detention at the fortress of Magdala.
Split into simpler sentences: Sahle Maryam was handed over to the Emperor Tewodoros and taken to Gondar. He was trained there in Tewodros's service, and then placed in comfortable detention at the fortress of Magdala.