 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 José Alava was sent from Madrid with a powerful naval fleet to stop the slave-raiding attacks from the Sulu Sea.The British presence was signalled when in 1798, the British Royal Navy, which had established a base in Sulu, bombarded Fort Pilar in Zamboanga.