The genesis of tactical board wargaming goes back to 1969. Up until that time, wargaming—which in the modern, recreational form only dated back to 1958—tended to concentrate on operational and strategic subjects. Charles S. Roberts of Avalon Hill had developed a wide range of strategic wargames based upon historical battles—the first of these being the 1961 releases of "Gettysburg" and "Chancellorsville", issued to coincide with the beginning of the centennial celebration of the American Civil War. AH issued a wide range of similar games in the years that followed, and established itself as the market leader in board wargames. However, most of these games were at the army, brigade, battalion, or regiment level. Few were at the more tactical levels.