Though the Lacerda and Gamitto expeditions were largely commercial, the third quarter of the nineteenth century saw scientific African expeditions. The Portuguese government was suspicious of exploration by other European nations, particularly those whose leasers held an official (often consular) position as Livingstone had, which their home countries could use to claim territory Portugal regarded as its own. To prevent this the Lisbon Geographical Society and the Geographical Commission of the Portuguese Ministry of Marine—at that time responsible for overseas territories as well as the navy—created a joint commission in 1875 to plan scientific expeditions to the area between Angola and Mozambique.