Union Day is a public holiday observed in Tanzania every April 26, commemorating the unification of Tanganyika and the People's Republic of Zanzibar and Pemba into the United Republic of Tanzania in 1964. The holiday marks the anniversary of the merger that followed the overthrow of the Sultan of Zanzibar during the Zanzibar Revolution. Celebrations typically include speeches by government officials and a parade in the city of Dar es Salaam. The event highlights Tanzania's historical journey from colonial rule, first under Germany and later the United Kingdom, to independence, with Tanganyika gaining independence in 1961 and Zanzibar in 1963. The day serves as a reminder of the significance of unity in the country's formation and development.