The General Act of the Berlin Conference dated 26 February 1885 introduced the principle of effective occupation, potentially damaging Portuguese claims, particularly in Mozambique where other powers were active. Article 34 required a nation acquiring land on the coasts of Africa outside of its previous possessions to notify the other signatories of the Act so they could protest such claims. Article 35 of the Act provided that rights could only be acquired over previously uncolonised lands if the power claiming them had established sufficient authority there to protect existing rights and free trade. This implied making treaties with local rulers, establishing colonial administration, and exercising police powers. Initially Portugal claimed the Berlin Treaty did not apply to its territories and that Portugal was not required to issue notifications or establish effective occupation, as Portugal's claim to the Mozambique coast had existed unchallenged for centuries.