|This article contains a translation of Wilhelm Steinitz from en.wikipedia.|
clarification, wilhem steinitz was not de facto world champion in 1866 but in 1872[change source]
Adolf Anderssen was world champion from 1851 to 1858, from 1860 to 1865, from 1868 to 1871. He was on top of chess world for 23 years. Adolf won all his matches against Zukertort, third unofficial world champion after Paul Morphy. Except for the 1865 and 1871 match, Steinitz defeated Anderssen in 1866, but Anderssen was not the champ at the time. Paulson drew Anderessen in 1860 match: 5 to 5, one draw. In 1860 he drew 11 game match vs Harrwitz. In 1861 he won 9 game match vs Harrwitz. Kolisch did it in 1862 match: 3 to 3 with 2 draws. Anderssen also drew Daniel Harrwitz in 1848 match: 5 to 5, this could be considered the first world championship match since at least 10 serious games were played! In 1864 he also drew Suhle, 3 to 3 with 2 draws. He lost a match in 1865 to Zukertort, regained the title in 1868. Since 1848 match was very competitive and Anderssen defeated everybody who met him thus he was the best player of his time.