Vasco da Gama was a 16th century Portuguese explorer who led the first European voyage to reach India by sea. The document provides details about da Gama's 1497 voyage, which had four ships and 170 crew members but only two ships and 55 crew returned, demonstrating the high mortality rates of these early voyages. It discusses the dangers sailors faced from disease, starvation and other threats without modern medicine and hygiene practices.