Spain declared war in 1578, planning to attack and capture Kota Batu, Brunei's capital at the time. This was based in part on the assistance of two Bruneian noblemen, Pengiran Seri Lela and Pengiran Seri Ratna. The former had travelled to Manila, then the centre of the Spanish colony. Manila itself was captured from Brunei, Christianised and made a territory of the Viceroyalty of New Spain which was centered in Mexico City. Pengiran Seri Lela came to offer Brunei as a tributary to Spain for help to recover the throne usurped by his brother, Saiful Rijal. The Spanish agreed that if they succeeded in conquering Brunei, Pengiran Seri Lela would be appointed as the sultan, while Pengiran Seri Ratna would be the new Bendahara.