Complex sentence: Afonso I of Kongo (1456-1545) reigned from 1505 to 1543 was a Christian and the first African king to be recognised in Europe who attempted to convert the kingdom to Christianity and stop Portuguese slavers.
Split into simpler sentences: Afonso I of Kongo (1456-1545), who reigned from 1505 to 1543, was a Christian and the first African king to be recognised in Europe. He attempted to convert the kingdom to Christianity and stop Portuguese slavers.