Alonso Alvarez de Pineda commanded a Spanish expedition that sailed along the Gulf of Mexio coastline from Florida to Cabo Rojo, Mexico, in 1519. He and his men were the first Europeans to explore and map the Gulf littoral between the areas previously explored by Juan Ponce De Leon and Diego Velazquez. Alverez de Pineda's voyage of "more than 300 leagues" ended when he encountered Hernan Cortes, who perceived him as a rival and arrested the messengers he sent ashore near Cortes's base at Villa Rica de la Vera Cruz on the Bay of Campeche. Alvarez de Pineda then withdrew back up the Mexican coast to the Rio Panuco, where he established a settlement of his own near the site of the future city of Tampico. Despite his pioneering exploration, however, Alvarez remains a shadowy figure.