The Pacific Ocean was for several centuries, from the discovery of the Strait of Magellan in 1520 until Cook's voyages in the 1700s, considered to be the "Spanish Lake." However, Spain was never a monolithic entity and this book then considers "Spanish" exploration in the Pacific from the perspective of the Basques, who have an important maritime tradition and were key figures in Pacific exploration. From Juan Sebastian Elkano's taking over command of the Victoria after Ferdinand Magellan's death and completing the first circumnavigation of the planet to Andres de Urdaneta's discovery of the north Pacific route from the Philippines to modern-day Acapulco, Mexico, Basque mariners and ships were pivotal in European incursion into this vast area.