May Day was the most important event in the urban calendar, a political festival on a mass scale that validated Vienna’s status as a socialist city. Marchers converged on the city centre from all quarters, led by the powerful Austrian Social Democratic Party. However, as political tensions heightened May Day marches became an arena of conflict, between different left-wing factions and an increasingly authoritarian national government. Tudor-Hart has candidly captured a marcher being detained. She herself was arrested shortly after.