He sent administrators, such as Theophilus Shepstone and Bartle Frere, to southern Africa to implement his system of confederation. Shepstone invaded and annexed the Transvaal in 1877, while Bartle Frere, as the new High Commissioner, led imperial troops against the last independent Xhosa in the 9th Frontier War. Carnarvon then used the rising unrest to suspend the Natal constitution, while Bartle Frere overthrew the elected Cape government, and then moved to invade the independent Zulu Kingdom.