Sixteen percent of the population is Sunni Muslim; their ancestors arrived in nineteenth-century Uganda from the east through Kenya and from the north through Egypt and Sudan. The Shafii legal school predominates in the central region of Buganda; the Maliki legal school is found in the north. Islamization was not accompanied by Arabization, as it was in North Africa, and Arabic is not widely spoken. Independent of Britain since 1962, postcolonial Uganda has been consistently ruled by Protestant Christians, except for the Idi Amin years (1971–79). Uganda joined the Organization of the Islamic Conference (OIC) in the early 1970s; both Id al-Fitr and Id al-Adha have been national holidays since the Amin era.