Sub-Saharan Africa was part of two large, separate trading networks, the Trans Saharan trade which bridged commerce between West and North Africa. Due to the huge profits from trade native African Islamic empires arose, including those of Ghana, Mali and Songhay. In the 14th century, Mansa Musa king of Mali may have been the wealthiest person of his time. Within Mali, the city of Timbuktu was an international center of science and well known throughout the Islamic World, particularly from the University of Sankore.