sentences:  In April 1964, the existence of this socialist republic was ended with its union with Tanganyika to form the United Republic of Tanganyika and Zanzibar, which became known as Tanzania six months later.By 1964, the country was a constitutional monarchy ruled by Sultan Jamshid bin Abdullah.Zanzibar had a population of around 230,000 natives, some of whom claimed Persian ancestry and were known locally as Shirazis.