The history of Anglican Diocese of Zanzibar is well inter-related with the history of University Mission of Central Africa and the liberation of Slave Trade in Zanzibar. Slave trade in Zanzibar was initiated by Portuguese who traded slaves in the 15 century. Portuguese were conquered in the war by the Oman in 1549. Zanzibar gradually built her transit trade from economic foundations achieved in the later part of the 18th century. From the early decades of the 19th century, Said bin Sultan (ruler of Zanzibar 1804 – 1856) moved his Capital from Muscat Oman to Zanzibar and encouraged among other things a broad range of commerce in the region. Slave trade was part of the Zanzibar commerce. The slave trade was promoted Under the Oman Arab rule and resulted of opening new slave market at Mkunazini. The Arabs continued slave trade until it was abolished by treaty of June 6, 1873. Slaves were obtained from the open market and about half of them were formerly captured from the mainland. They were transited at coastal ports such as Kilwa, Kaole, Bagamoyo and Pangani (on the mainland coastline) before packed on board in the dhows to Zanzibar. Most slaves were procured in the region around Lake Nyassa. The journey down to the coast caused much suffering and pain to slaves, some died of exhaustion, disease, malnourishment, and whoever attempted to escape was shot. Bigger external demands for slaves and also ivory, as well as higher prices for slaves, offered in the coastal ports enticed the coastal traders to heatedly search the interior.