overland to Massangano and their supply lines to such an extent that they could not invest the aringa. Once the Portuguese began to retreat, the chikunda made night attacks that caused the Portuguese forces to scatter with heavy losses. Although the da Cruz were subsequently left in peace for about 20 years, and recognised as effectively autonomous, they made little use of their military successes and never became more than a bandit state, based on the slave trade and the tolls it could impose on river traffic, as they occupied a sparsely-populated and infertile area. The formal abolition of the institution of slavery in Mozambique 1875 and of the prazo system in 1878 had little immediate effect on the Afro-Goan and Afro-Portuguese families. Just as the formal abolition of the slave trade in 1830 had simply promoted a clandestine trade that lasted into the 20th century, so the abolition of slavery made no immediate change to the unfree status and situation of the peasants in the minor states. Chikunda states As economical and environmental degradation coupled with upheaval and migration of peoples took its toll on the prazos, certain ex-chikunda took the initiative of fleeing north and northwest and establish their own states, modelled on the prazos. The most successful of these may have been José Rosário de Andrade, known as Kanyemba ("the ferocious"), who began assembling a private army in the 1870s and settled in the region of Bawa, two hundred kilometers west of Tete, from which he either traded with or raided the surrounding countryside. In the 1880s, this warlord was said to have 10000 chikunda at arms. Andrade died in the late nineteenth century, and by 1903 the Portuguese would defeat his state along with the rest of runaway chikunda forces. The end of the chikunda The Scramble for Africa In the second half of the 19th century, several European powers had increasing interests in Africa that could challenge Portugal's territorial claims, as it had no effective presence in the area between Angola and Mozambique, and little in many areas within the present borders of those countries. Although the Portuguese Minister of Marine, Andrade Corvo, who also had responsibility for the overseas territories, attempted bilateral negotiations with Britain in 1879, 1882 and 1884 to fix the Ruo River (now the south-eastern border of Malawi) as the northern limit of Portuguese rule, these talks were overtaken by the