In 1605 the VOC conquered the island of Tidore. The Portuguese had a number of bases on the island; after their defeat by the VOC, they left the Molucca islands for good. The subjection of the sultan of Tidore, who had long been the major competitor and enemy of the sultan of Ternate, was of strategic importance to the VOC. It enabled the Company to secure a trade monopoly in the Molucca islands. As well as food crops, Tidore also produced cloves. After the VOC's conquest of the Portuguese territories, the sultan of Tidore appealed to the Spanish in Manila for assistance. The Spanish who succeeded in establishing a foothold on Tidore remained on the island until 1663. Only after their departure was the VOC able to gain complete control over the trade there. The Company's presence on Tidore was always limited to small military posts; the island lacked a good harbour, and so a trading station was never opened there.