In March 1578, a fresh Spanish fleet had arrived from Mexico and settled at the Philippines, they were led by De Sande, acting as Capitán-General, he organised an expedition from Manila for Brunei. The expedition consisted of 400 Spaniards and Mexicans, 1,500 Filipino natives and 300 Borneans. The campaign was one of many, which also included action in Mindanao and Sulu. The racial make-up of the Christian side was diverse since it were usually made up of Mestizos, Mulattoes and Amerindians (Aztecs, Mayans and Incans) who were gathered and sent from Mexico and were led by Spanish officers who had worked together with native Filipinos in military campaigns across the Southeast Asia. The Muslim side though was also equally racially diverse. In addition to the native Malay warriors, the Ottomans had repeatedly sent military expeditions to nearby Aceh. The expeditions were composed mainly of Turks, Egyptians, Swahilis, Somalis, Sindhis, Gujaratis and Malabars. These expeditionary forces had also spread to other nearby Sultanates such as Brunei and had taught new fighting tactics and techniques on how to forge cannons.