Navigations: The Portuguese Discoveries and the RenaissanceMalyn Newitt, Reaktion Books, £15.95WHAT is often called The Age of Discovery, when Spanish and Portuguese explorers reached the southern coast of Africa, the Americas, and the Pacific, is something of a misnomer. When Vasco de Gama reached the coast of east Africa in March 1498, he “discovered” pre-existing trade routes across the Indian Ocean that had been established by Yemeni Arab merchants hundreds of years before.