The Portuguese State of India, headquartered in Goa, was a network of key cities which controlled the maritime trade in the Indian Ocean: Sofala was the base for Portuguese operations in East Africa and was supported by Kilwa to better control the Mozambique Channel; from here, the routes took the trade to Goa which was the hub for the rest of the operations and where the India Convoy ships out of Europe arrived; from Goa, going northwards, the trade would be protected by the North and Adventurers Fleets all the way to Daman and Diu which oversaw the northern trade and the Gulf of Cambay; while the Fleet of the North escorted merchant ships the Adventurers Fleet would also seek to disrupt the Mecca trade between northern India's Muslims and the Arabian Peninsula; the Diu Fleet would then connect the trade to Hormuz which controlled the Persian Gulf routes and interrupted the Basrah-Suez trade; southwards from Goa, the Cape Comorin Fleet would escort the Goa merchants to Calicut and Cochin in the Malabar Coast and to Ceylon and the connection to the Bay of Bengal; in the Bay of Bengal, the most lucrative trade was in the Coromandel Coast where such settlements as São Tomé of Mylapore and Pulicat served as hubs; it was in the Coromandel and Ceylon settlements where the ships out of the Malacca 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.