Islam arrived to Africa in the earliest days of Islam, when Muslims fleeing persecution in Mecca arrived in what was then the Aksumite empire. Islam spread to Africa via passages through the Sinai Peninsula and Egypt and through Islamic Arab and Persian traders and sailors. Islam's first muezzin, Bilal ibn Ribah, was also of Northeast African(Habasha) descent. From 1869 to 1914 Islam in Africa probably doubled in size of countries. Despite its large contribution to the makeup of the continent, Islam is predominantly concentrated in North and Northeast Africa, as well as the Sahel region.