Rhodes had already tried and failed to get a mining concession from Lobengula, king of the Ndebele of Matabeleland. In 1888 he tried again. He sent John Moffat, son of the missionary Robert Moffat, who was trusted by Lobengula, to persuade the latter to sign a treaty of friendship with Britain, and to look favourably on Rhodes' proposals. His associate Charles Rudd, together with Francis Thompson and Rochfort Maguire, assured Lobengula that no more than ten white men would mine in Matabeleland. This limitation was left out of the document, known as the Rudd Concession, which Lobengula signed. Furthermore, it stated that the mining companies could do anything necessary to their operations. When Lobengula discovered later the true effects of the concession, he tried to renounce it, but the British Government ignored him.