Rodrigo "Ruy" López de Segura (c. 1530 – c. 1580) was a Spanish chess player, author, and Catholic priest whose 1561 treatise Libro de la invención liberal y Arte del juego del Axedrez was one of the first books about modern chess in Europe. He made great contributions to chess opening theory, including in the King's Gambit and the Ruy López (or Spanish) opening that bears his name. López was also the strongest player in Spain for about 20 years. Life López was a native of Segura de León, a town in Extremadura, Spain. In 1559, while living in Zafra, López was called to Rome by Pope Pius IV on ecclesiastical business. During his stay in Rome, López played chess with the locals. He apparently acquitted himself well, although the only account of these games is given in a single sentence by López himself. One of those players was Il Puttino, an epithet for a young Leonardo di Bona. López also learned the term gambit from the Italian players. In Italy López encountered Pedro Damiano's treatise on chess, Questo libro e da imparare giocare a scachi et de li partiti, and did not find much value in it. This may have inspired López to write his own book, Libro de la Invencion liberal y Arte del juego del Axedrez, which was published in 1561. López was the strongest player in Spain for nearly twenty years; his nearest rivals were Alfonso Ceron (of Granada) and Medrano. López and Ceron played before King Philip II of Spain, impressing him enough for López to earn a benefice and a golden chain displaying a rook. López was also esteemed for his ability at blindfold chess. Alessandro Salvio writes that López travelled to Rome again, in 1572. It is more probable, however, that López visited Rome only once (in 1559) and that Salvio's chronology is incorrect. Around the year 1574, López was still at the royal court in Spain when di Bona, then Paolo Boi, arrived on their tours of Europe. Their meetings – which also included Ceron – are sometimes considered the first international chess tournament. Boi and a much-improved di Bona defeated López and Ceron in Madrid, in the presence of Philip II. López was again able to best Ceron. The years of López' birth and death can be estimated only very approximately; a lifespan of ca. 1530-1580 is commonly given without evidence.