Ruy Lopez de Segura (1530-1580) was a Spanish priest whose book Libro de la invención liberal y arte del juego del Axedrez was one of the first fundamental chess books in Europe, only after Pedro Damiano’s. He studied and lived in Salamanca.
He was considered by many to be the 1st unofficial world chess champion and was probably the father of international competition when he won the first international chess tournament in Madrid, Spain in the year 1560. He would go on later to Rome in 1571 and defeat Giovanni Leonardo di Cutri and Pablo Boi, the two best Italian players.
Leonardo and Boi would have their revenge against Lopez in 1575 in presence of King Felipe II. His name lives on in both a popular chess opening, as well in the chess book he wrote in 1561.
His opening, generally known as the Spanish Opening (many English players actually refer to it as the Ruy Lopez) is one of the most famous of all openings.