 Tippu Tip, the most powerful of Zanzibar's slave traders of the 19th century, was well known to Stanley, as was the social chaos and devastation brought by slave-hunting.It had only been through Tippu Tip's help that Stanley had found Livingstone, who had survived years on the Lualaba by virtue of Tippu Tip's friendship.Now, Stanley discovered that Tippu Tip's men had reached still further west in search of fresh populations to enslave.