Vasco de Balboa was a Spanish explorer born in 1475 who worked for a rich merchant before sailing with Columbus on his second voyage to the new world. In 1506, he discovered Puerto Rico and was the first European to see the Pacific Ocean, which he named the South Sea. As governor of Panama, Balboa crossed the Isthmus of Panama in 1513 and became the first European to see the Pacific Ocean. However, he was later accused of treason and beheaded in 1519.