Wilhelm Steinitz was the first official world chess champion, holding the title from 1886 — when he defeated Johannes Zukertort in the inaugural match in New York, St. Louis and New Orleans — until 1894, when Emanuel Lasker took the crown in Montreal. Before that he had already been recognised as the world’s strongest player for nearly two decades after his 1866 match victory over Adolf Anderssen, who was at the time the de facto best player in the world.
His significance to chess far outstrips the championship years themselves. Steinitz invented the modern theory of positional play. Before him, the dominant chess culture — the Romantic school of Anderssen, Morphy, Kieseritzky — held that the strongest move was the most aggressive move, and that gambits, sacrifices and direct attacks on the king were the legitimate way to win. Steinitz disagreed. He argued that chess was governed by structural laws — pawn structure, piece coordination, space, the centre, the safety of the king — and that the player who accumulated small positional advantages would inevitably defeat the player who relied on tactical fireworks.
This was heresy at the time. Steinitz had to defend his theory not only in writing but at the board, and he did so by beating every significant player of his era using exactly the methods he advocated. Over decades of practice, his system became the framework that every subsequent world champion learned to think within. Lasker built on it. Capablanca refined it. Botvinnik systematised it for the Soviet School. Karpov and Carlsen, in different centuries, both played pure Steinitzian chess at the highest level.
His later years were difficult. He emigrated to the United States in 1883 and became a US citizen, but financial pressures and declining health weighed on him. After losing the title to Lasker in 1894 he attempted to win it back in 1896-1897, but Lasker proved too strong. Steinitz died in 1900 in poverty, in Wards Island, New York.
The chess he left behind has continued to shape every era since. The encyclopaedia of opening theory that you can browse on this site exists in its modern form because Steinitz first argued that openings should be studied scientifically rather than as a catalogue of attacking ideas. Every player who has held the title since — including the current world champion — owes Steinitz the framework within which they think.