Complex sentence: However, not all slaves kept the culture of their ancestors, the Bakongo were Catholics, because the kingdom of Kongo had voluntarily converted to Catholicism in 1491, after of the Portuguese conquered this territory.
Split into simpler sentences: However, not all slaves kept the culture of their ancestors. The Bakongo were Catholics, because the kingdom of Kongo had voluntarily converted to Catholicism in 1491, after of the Portuguese conquered this territory.