Why did the Mali kingdoms go into decline? Who was allowed to conquer in the wake of their weakness? (Site 1)

Mali Kingdoms went into decline because they were at constant struggle with the Songhai Kingdom for African domination. They constantly either fought real wars or economic and cultural wars on imposing themselves as the biggest kingdom and this weakened them a lot.

Those who conquered them were Moroccan fusiliers who had firearms whereas Mali didn't have such highly advanced technology at the time. They led a long battle but lost eventually just like Songhai's did and with that the Kingdom of Mali ended with its last emperor.