The Anglo-Portuguese Treaty
In the 1830s and 1840s, however, whether by treaty in the case of Spain, or unilateral action in the cases of Portugal and Brazil, the Royal Navy was given a free hand and, from the 1830s onwards, started to mount anti-slavery patrols off the Congo estuary. The Portuguese, by contrast, were relatively inactive, both militarily and commercially, but this did not prevent their trying to promote their claims to the territory, which they defined as stretching between the latitudes 5° 12' and 8° 00' south. From the Portuguese point of view, the problem about the first assertion was that in contrast to Angola, to the south of the 8th parallel, they had never exercised any significant degree of sovereignty over the Congo and the coast around it. That part of the Portuguese case that was based on earlier recognition had perhaps a somewhat better foundation.