Portuguese on Sri Lanka, the VOC made contact with the Kingdom of Kandy. Confidence in the Kandyan forces rose after they defeated a Portuguese army at the Battle of Gannoruwa in March 1638. Shortly thereafter, the VOC and Rajasinha II of Kandy signed a treaty in May 1638, by which the VOC promised to aid Kandy in its continuing war against the Portuguese in exchange for a monopoly on many trading goods. The combined VOC and Kandyan forces gradually wore down the Portuguese forces, pushing them out of their strongholds across the island. Batticaloa on the East coast fell to Dutch forces in 1639, then Negombo on the West coast in 1640. Galle was captured after a siege in 1640, providing the Dutch with a port and naval base. However the Kandyans became suspicious of their new allies, correctly believing that the VOC goal was not just to remove the Portuguese from Sri Lanka, but to replace them as the colonial power. The alliance fell apart after a ceasefire was agreed between Dutch and Portuguese forces at some point between 1641 and 1645. Kandyan forces engaged in skirmishing with both Dutch and Portuguese forces over the following years, but were unable to make inroads. The VOC and Kandy returned to negotiations and reformed their alliance in 1649, albeit on different terms. Meanwhile, the Iberian Union had ended in 1640, depriving the Portuguese colonies of Spanish support. The Peace of Münster in 1648 had ended the Dutch war with Spain (but not Portugal). These developments together acted to free up Dutch forces from other conflicts, allowing them to concentrate on their attacks on Portuguese colonies. The VOC-Kandy alliance went on the offensive in Sri Lanka from 1652. Whilst Kandy controlled the interior of the island, it was landlocked and the Dutch fleet were able to dominate the coast. Two naval actions were fought between the Dutch and Portuguese on 23 March near Colombo and 2 May 1654 near Goa; the Portuguese won the first battle but lost their entire Indian subcontinent fleet in the second. The Dutch placed the main Portuguese base of Colombo under siege in 1655. Rajasingha no longer trusted the Dutch and insisted that Colombo be ceded to Kandy as soon as it fell. However, when the city finally fell in 1656, the Dutch immediately closed the gates against their ally. Faced with a complete breakdown in relations