Indian Ocean trade Madagascar at this time leaving behind a lasting cultural and genetic legacy. Chinese fleets under Zheng He criscrossed the Indian Ocean during the early part of the 15th century. The missions were diplomatic rather than commercial, but many exchanges of gift and produces were made. The Portuguese under Vasco da Gama discovered a naval route to the Indian Ocean through the southern tip of Africa in 1497–98. Initially, the Portuguese were mainly active in Calicut, but the northern region of Gujarat was even more important for trade, and an essential intermediary in east-west trade. Venetian interests were directly threatened as
Portuguese India Armadas (1497–99) to the end of 1563. It is conserved at the Pierpont Morgan Library in New York City (ms. 525). Another codex of the same nature is the "Memória das Armadas que de Portugal passaram à Índia" ("Memory of the Armadas that from Portugal passed to India") or "Livro das Armadas", held by the Academia das Ciências in Lisbon. It covers the period from 1497 to 1567 (although missing the armada of 1517). The first Portuguese chronicler to attempt a systematic chronology of the India Armadas seems to have been Diogo do Couto, in his appendix to João de Barros's