An influx of immigrants from Oman and Yemen during the following centuries increased the number of Muslims in Somalia, Eritrea and Ethiopia. In the coastal areas of today’s Eritrea most inhabitants are Muslims and Islamic law gradually took root. Their coexistence with Christianity was not always an easy one and the sultans who ruled over parts of Ethiopia sometimes came into open conflict with the Christian kings. Yet, historians generally agree that Muslim sultans in Ethiopia were tolerant with their Christian subjects; forced conversions were rare.
In 1668, an imperial decree was issued in Gondar declaring that Muslims and Jews would have to live apart from Christians, but they were allowed to practice their religion freely in their own quarters. Religious squabbles did not end there, but by the nineteenth century peaceful conditions were established for the popular interest. Political conflicts between Ethiopia and Somalia and Eritrea, are not based on religious differences per se. Today about 35 % percent of Ethiopia's population is Muslim, mostly Sunnis, members of the largest sect of Islam.