Answer based on context:

But its success depended greatly on the use of Portuguese mercenaries who proved unreliable and troublesome. Arakan lost the port city of Syriam in Lower Burma in 1603 when its Portuguese governor Filipe de Brito e Nicote declared that he was now loyal to the Portuguese viceroy of Goa. After two failed expeditions by the Arakanese navy to retake the port in 1604 and 1605, Arakan gave up its claims on the Lower Burma coastline. Arakan's Portuguese troubles were not yet over. In 1609, its northern territories at the edge of Ganges delta and off Chittagong came under threat by the Portuguese mercenaries and the Mughal government in Bengal. In March 1609, 400 Portuguese mercenaries, led by Sebastian Gonzales Tibao, seized the Sandwip island. Meanwhile, the Mughal governor of Bengal tried to take over Noakhali District. Min Yazagyi was forced to enter into an alliance with the Portuguese to drive out the Mughals. After the Mughals were driven out, Gonzales promptly seized the Arakanese navy, and began raiding as far south as Lemro river. Later, the Portuguese viceroy at Goa sanctioned an attack on Mrauk-U itself. In November 1615, a fleet of 14 Portuguese galliots and 50 smaller war boats led by Francis de Meneses sailed up the Lemro. Alas, the fleet was driven back by Arakanese defences, which included broadsides of a few Dutch ships. Two years later, King Min Khamaung finally captured Sandwip, and put most of its inhabitants to death.

What happened first: seized the Sandwip island or seized the Arakanese navy?
seized the Sandwip island