route often laid anchor because they connected the Indian Ocean to the South China Sea; the Malacca Fleet patrolled the Singapore Strait and the routes diverted to Celebes and what is now Indonesia at large in the south, and northwards to China and Japan; China provided silk and china to Macau from where the 'Silver Carrack' connected to Japan where several products were exchanged for Japanese silver. Casus belli At dawn on February 25, 1603, three ships of the Dutch East India Company (VOC) seized the Santa Catarina, a Portuguese galleon. It was such a rich prize that its sale proceeds doubled the capital of the VOC. The legality of keeping the prize was questionable under Dutch statute and the Portuguese demanded the return of their cargo. The scandal led to a public judicial hearing and a wider campaign to sway public (and international) opinion. As a result, Hugo Grotius in The Free Sea (Mare Liberum, published 1609) formulated the new principle that the sea was international territory, against the Portuguese mare clausum policy, and all nations were free to use it for seafaring trade. The 'free seas' provided suitable ideological justification for the Dutch to break the Portuguese monopoly through its formidable naval power. Insertion in the East: Batavia challenges Goa The Portuguese East Indies relied on four strategic bases: Goa, Bombay-Bassein-Dio, Malacca, and Macau. The first connected India with Portugal proper (Ceuta), Malacca connected Goa to the Indian Ocean trade via Cape Comorin and Ceylon; and Macau was the hub for the trade routes stretching from the South China Sea to the Sea of Japan and to the Spice islands, east of New Guinea in Australasia. The other locations were important but not crucial: Including Diu along with the Bombay Harbour (until the English acquisition) controlled the approaches to the smaller Gulf of Cambay and to the larger Arabian Sea as well. Hormuz was Portugal's protectorate for a short time, during which it was the keystone of the Persian Gulf trade happening between Persia, Arabia, Mesopotamia, and rest of Asia and Africa. If both Diu and Hormuz would fall, that would prevent the Near Eastern markets from being taxed by Portugal, which would deny Lisbon the revenue from the southernmost course of the Silk route. It was a lucrative trade but not as essential to the Indian Oceanic spice trade network at large. After the fall of Hormuz