Immensely popular in recent years, Sudoku dates as far back as 1783, when Swiss mathematician Leonhard Euler created Latin Squares. In Euler's puzzle every number or symbol had to appear only once in each row or column of a grid. In the late 1970s Dell puzzle magazines began publishing a nine-by-nine grid puzzle called Number Place. Then, in the 1980s, a Japanese publisher refined the game and called it Sudoku, combining su (number) and doku (unique). Sudoku came back West when a retired judge from New Zealand saw a puzzle in a Japanese bookshop in 1997, developed a computer program to create Sudoku, and in 2004 persuaded The Times of London to publish them.