 Spanish attacks on Jolo were now directed at weakening British trading interests in the south.In 1784, Aguilar conducted a series of unsuccessful assaults against Jolo and in 1796, Spanish Admiral Jose Alava was sent from Madrid with a powerful naval fleet to stop slave-raiding attacks coming from the Sulu Sea.British presence was signaled when in 1798, Fort Pilar in Zamboanga was bombarded by the British navy, which had established a base in Sulu.