Welsh industrialist Robert Owen takes charge of a mill at New Lanark and develops it as an experiment in paternalistic socialism

George Rapp and his followers establish a utopian community in Pennsylvania and call it Harmony

The English socialist Robert Owen purchases New Harmony from the Rappists, to test his utopian theories in a new context

The young Friedrich Engels is sent from Germany to manage the family cotton-spinning factory in Manchester

Karl Marx and Friedrich Engels meet in Paris and become life-long friends

Friedrich Engels, after running a textile factory in Manchester, publishes The Condition of the Working Class in England

At a congress in London Engels persuades a group of radical Germans to adopt the name Communist League

The Communist Manifesto, by Marx and Engels, is published in Paris with the ringing slogan: 'Workers of the world, unite!'

A utopian community dedicated to the sharing of both property and sexual favours is established by John Humphrey Noyes near Oneida, New York

Expelled from Germany after the year of revolutions, Marx makes his home in tolerant London

The First International is established in London, with Karl Marx soon emerging as the association's leader

The first volume of Das Kapital is completed by Marx in London and is published in Hamburg

Lenin's elder brother Alexander, while still a student, is executed for his part in a plot to assassinate the tsar, Alexander III

The Second International is established by the Socialist parties of ten nations, meeting at a congress in Paris

Lenin is arrested in St Petersburg, along with other members of the Union for the Struggle for the Liberation of the Working Class

Lenin and comrades launch in Munich a radical newspaper, Iskra ('the spark')

In his pamphlet What is to be done? Lenin argues for early action to promote revolution

Lenin's supporters become known as the Bolsheviks ('majority') as opposed to the Mensheviks ('minority') after a split at the party's Second Congress

The first soviet ("council") of workers is set up in St Petersburg, introducing a word of great significance in Russian Communist history

At a conference in Prague Lenin forms the Bolsheviks into a separate political party with himself as leader

The German authorities allow Lenin to travel home from Switzerland through Germany, hoping for Communist disruption of the Russian war effort

Lenin expounds in Petrograd the new theory of his April Theses, predicting the possibility of imminent revolution

An armed uprising in Petrograd disperses after Lenin declines to give support

Trotsky is imprisoned and Lenin flees to Finland as Russia's Provisional Government cracks down on the Bolsheviks

Lenin, in disguise, returns from Finland to Petrograd, where he hides in the flat of a party worker