Up until 1917 Russia was ruled by an Autocrat (was ruled by one person who can also be a dictator) - The Tsar. He was well meaning but inefficient and maintained his position by means of the secret police called the "Okrana".
The political status of Russia at the beginning of the 20th century gave rise to a number of political parties. During the 1870ís a group of intellectuals began to study the writings of Karl Marx and as their numbers gradually increased, many were exiled to Switzerland. Their view developed amongst these people that revolutionary changes in Russia would only come about with the support of industrial workers, not peasants and by political action, not terrorist methods. From this group the Social Democratic party was found in Minsk in 1898. Although many of the members were arrested, the party still existed in Russia and the most strong willed and single minded member, Vladimir Ulyanov, later known as Lenin, rose as leader.
From the Social Democrats party came the Mensheviks and the Bolsheviks. The Social democrats split on the issue of organisation. Lenin wanted to restrict the party to dedicated people but many members, including Trotsky and Plekhanov wanted the party to grow with as many well-wishers as possible. From these two groups, Lenin got a small majority which became the Bolsheviks, and his opponents within the party became the Mensheviks.
Zemstov were a group of local councils which did involve some democracy in Russia