Sultanate of Tidore (Indonesian: Kesultanan Tidore, sometimes Kerajaan Tidore) was a sultanate in Southeast Asia, centered on the Spice Islands of Tidore, a rival of Sultanate of Ternate for control of the spice trade. The Sultanate of Tidore ruled most of southern Halmahera, and, at times, controlled Buru, Ambon and many of the islands off the coast of New Guinea. In 1605 war broke out with neighbouring Ternate. Tidore had established a loose alliance with the Portuguese in the seventeenth century who had several forts on the island. Ternate had allied with Dutch traders.