Paul Keres (7 January 1916 – 5 June 1975) was an Estonian chess grandmaster and chess writer. He was among the world's top players from the mid-1930s to the mid-1960s, and narrowly missed a chance at a World Chess Championship match on five occasions. As Estonia was repeatedly invaded and occupied during World War II, Keres was forced by the circumstances to represent the Soviet Union (1940–1941, 1944–1975) and Nazi Germany (1941–1944) in international tournaments. Keres won the AVRO 1938 chess tournament, which led to negotiations for a title match against the reigning World Champion Alexander Alekhine, but the match never took place due to the outbreak of World War II in 1939. Keres was runner-up in the Candidates Tournament on four consecutive occasions from 1953 to 1962. Due to these and other strong results, many chess historians consider Keres along with Viktor Korchnoi to be the strongest players never to become world champion. Robert McFadden of The New York Times described Keres as having "elegant manners and an informal but unflappable bearing", and stated that "his competitiveness and well‐known sense of fairness made him one of the game's most popular figures". Widely admired by Estonians to this day, he was nicknamed "Paul the Second", "The Eternal Second", and "The Crown Prince of Chess".