La Bourdonnais

Louis-Charles Mahé de La Bourdonnais was a French master who dominated competitive chess before an official world championship existed. Recent historical research places his birth in Paris in 1797; he died in London in 1840. His surname appears in several forms, including La Bourdonnais and Labourdonnais.

His central competitive legacy is the 1834 series against the Irish player Alexander McDonnell in London. They played six matches totaling 85 games, without chess clocks and under conditions far less standardized than today's. La Bourdonnais achieved the better overall result. The games were recorded and circulated, allowing later generations to study their attacks and pawn races, positions in which both sides try to reach the last rank first and replace a pawn with a queen, rook, bishop, or knight.

The series is sometimes described as an unofficial world championship. That phrase reflects the players' standing as the strongest of their time, but the official World Chess Championship did not yet exist. La Bourdonnais also edited Le Palamède, launched in 1836 and recognized as one of the earliest chess periodicals, helping turn master games into public study material.