ruthless use of modern weaponry to kill opponents, and above all his relentless determination opened the route to the Upper Congo. In later years, Stanley would write that the most vexing part of his duties was not the work itself, nor negotiating with the natives, but keeping order amongst the ill-assorted collection of white men he had brought with him as overseers, who squabbled constantly over small matters of rank or status. "Almost all of them", he wrote, "clamoured for expenses of all kinds, which included ... wine, tobacco, cigars, clothes, shoes, board and lodging, and certain nameless extravagances" (by which he meant attractive slaves to warm their beds). Exhausted, Stanley returned to Europe, only to be sent straight back by Leopold, who promised him an outstanding assistant: Charles 'Chinese' Gordon (who did not in fact take up Leopold's offer but chose instead to go to meet his fate at Khartoum). "It is indispensable", instructed Leopold, "that you should purchase for the (i.e., Leopold himself) as much land as you can obtain". Having established a beachhead on the lower Congo, in 1883 Stanley set out upriver to extend Leopold's domain, employing his usual methods: negotiations with local chiefs buying sovereignty in exchange for bolts of cloth and trinkets; playing one tribe off another; and if need be, simply shooting an obstructive chief and negotiating with his cowed successor instead. However, as he approached Stanley Falls at the junction between the Congo proper and the Lualaba (close to the general vicinity of Central Africa where he had found Livingstone six years before), it soon became clear that Stanley's men were not the only intruders. Dealings with Zanzibari slave traders Tippu Tip, the most powerful of the Zanzibari slave traders of the 19th century, was well known to Stanley, as was the social chaos and devastation that slave-hunting brought. It had only been through Tippu Tip's help that Stanley had found Livingstone (who himself had survived years on the Lualaba by virtue of Tippu Tip's friendship). Now, Stanley discovered, Tippu Tip's men had reached still further west in search of fresh populations to enslave. Four years before, the Zanzibaris had thought the Congo deadly and impassable, and warned Stanley not to attempt to go there, but when Tippu Tip learned in Zanzibar that Stanley had survived, he was quick to act. Villages throughout the region had been burned and depopulated. Tippu Tip