John Harrison Clark or Changa-Changa (c. 1860–1927) effectively ruled much of what is today southern Zambia from the early 1890s to 1902. He arrived alone from South Africa in about 1887, reputedly as an outlaw, and assembled and trained a private army of Senga natives that he used to drive off various bands of slave-raiders. He took control of a swathe of territory on the north bank of the Zambezi river called Mashukulumbwe, became known as Chief "Changa-Changa" and, through a series of treaties with local chiefs, gained mineral and labour concessions covering much of the region.