The story of Sudoku begins not in Japan, but in Switzerland. In 1783, mathematician Leonhard Euler introduced the concept of "Latin Squares," grids where numbers or symbols appeared only once per row and column. Euler's work laid the mathematical foundation for what later became Sudoku. In the late 19th and early 20th centuries, puzzle creators experimented with these ideas, and number puzzles appeared in French newspapers around 1895. These early versions used 9x9 grids with numbers but had simpler rules than modern Sudoku.
They eventually disappeared, but the concept survived. In the late 1970s, the American magazine Dell Pencil Puzzles and Word Games introduced a puzzle called "Number Place," created by retired architect Howard Garns. It followed the rules of modern Sudoku, requiring players to fill numbers 1 to 9 in rows, columns, and 3x3 boxes without repetition. First published in 1979, the puzzle remained relatively unknown in the United States. In the 1980s, Japanese publishers discovered it, and Nikoli, a famous puzzle company, gave it the name "Sūji wa dokushin ni kagiru," meaning "numbers must be single." This long phrase was shortened to "Sudoku," and the puzzle quickly became popular in Japan throughout the 1980s. Nikoli also refined the rules, ensuring puzzles had only one unique solution, which improved fairness and logic.
By the 1990s, Sudoku was Japan's top logic puzzle, though the rest of the world had not yet embraced it. Everything changed in 2004 when British judge Wayne Gould developed a computer program to generate Sudoku puzzles. He persuaded The Times of London to publish them, and the first appeared on November 12, 2004. The response was overwhelming, with readers becoming addicted and demanding more. Other British newspapers soon joined, and within months Sudoku had spread across Europe, reaching Germany, Italy, and France. By 2005, it returned to the United States, but this time as a worldwide phenomenon. Books, websites, mobile apps, and television features fueled its popularity. Tournaments emerged, and in 2006 the first World Sudoku Championship was held in Italy, attracting international competitors. Since then, annual championships have taken place in different countries. Meanwhile, Sudoku apps dominated mobile gaming, and countless variations appeared, including Killer Sudoku, Samurai Sudoku, and Sudoku X, as well as larger grids like 16x16 and 25x25 for advanced players.
Online Sudoku platforms attracted millions of daily users, and educators adopted it to teach logic and critical thinking. Psychologists praised Sudoku for improving memory, reasoning, and focus, while scientists studied its potential benefits against cognitive decline. During the COVID-19 pandemic, Sudoku's popularity surged once more, as players sought relaxation, challenge, and mental exercise from home. Today, Sudoku can be found everywhere: in newspapers, books, apps, and websites across the globe. From Euler's Latin Squares to Howard Garns' Number Place, from Nikoli's renaming to Wayne Gould's global spread, Sudoku has evolved into one of the world's most beloved and enduring logic puzzles, a true global classic that continues to challenge and entertain millions of minds daily.