[1] In January 1603, the Portuguese captain, André Furtado de Mendonça, requested the Spanish governor of the Philippines, Pedro Bravo de Acuña, to assist him in capturing the Malukus from the Ternateans with men and supplies as the Portuguese lacked both.

The Ternatean Sultan, Saidi Berkat, asked for help from the Javanese and the Mindanoas, and the Dutch assisted him in fortifying his capital.

[2] On January 20, a squadron of 200 Spanish and 5 ships under Juan Xuarez Gallinato (who had returned from his failed expedition in Jolo), was well supplied and arrived on Tidore on February 14.

The Ternateans stubbornly defended the fort and finally gave up to allow the Spanish and Portuguese to approach Ternate city.

The Ternateans were well supplied with weapons and safe behind their walls, resisting the Iberians fiercely with their Dutch allies.