Ibrahim sought to undermine the semi-autonomous Arab regiments ("junds") which were the basis of the aristocracy's power, by supplanting them with loyal black African slave-soldiers (""Abid"" or ""Sudan"") at the core of the Ifriqiyan army. At the inauguration of Raqqada in 878, Ibrahim had the palace guard of his predecessor massacred at the tower of Abu al-Feth in order to make way for his own new Sudanese guard. Ibrahim expanded the Sudanese regiments (later supplemented by white European Slavs or "Saqaliba") to as much as 10,000, much to the chagrin of the Arab "jund" commanders. The Arab nobility resented not only being eclipsed, but also the hefty taxes and requisitions imposed by Ibrahim to maintain such a large standing army.