What is "rumaliza"

Muhammad bin Khalfan bin Khamis al-Barwani (born c. 1855), commonly known as Rumaliza, was a Swahili slave and ivory trader in East Africa in the last part of the nineteenth century. With the help of Tippu Tip he became Sultan of Ujiji. At one time he dominated the trade of Tanganyika, before being defeated by Belgian forces under Baron Francis Dhanis in January 1894.