One interesting aspect regarding the history of chess is that a number of variations of have been played in different countries for hundreds of years. As the early trade routes expanded from India, interest in the game became popular. During the 6th century, Persians began to play chess after they were invaded and conquered by the Muslims. As more countries were conquered, and the people assimilated the culture of the conquering countries, the game was played more. Eventually it spread to Europe. The Chinese have their own variation of the game. The Japanese have devised their own version which is known as Shogi.
The history of chess included an evolution into what it's known as today. This occurred in the 15th century. Prior to that time, at about 1000 AD, the games spread to Italy and Spain. As the Vikings conquered more countries, the game spread to the Scandinavian countries and as far as Iceland. In the central countries of Europe, the game was well known by 1100 to 1200 AD. By that time, the rules had been established and are the rules that apply to the game today. Although the game of chess was known in Russia, players of the game didn't have the mastery of chess that players in other countries did until the Russian Revolution in 1917.
The first championship which attracted experts from around the world is important to the history of chess. It was held in England, and was known as the London Tourney of 1851. The English expert Staunton was the master that today's chess pieces used in tournaments around the world are named after. The ways that expert chess players theorized the game changed during the latter part of the 20th century. During the 1970's, chess games which were computerized and pre-programmed hit the market. During this century, it's expected that more computers will be used to analyze how chess games are played.