Blazej Vilim was born on 3 February 1909 in Prague [Czechoslovakia, later the Czech Republic], the youngest of three children. His father died of typhoid as a prisoner during the First World War, while his mother was active in the Communist co-operative "Vcela".

Vilim was apprenticed as a metal worker in Prague and also studied externally for matriculation examinations. In 1928 he joined the Communist Youth Organisation and came to the notice of prominent Party members. He then published a resolution against the leadership of the Czech Communist Party in which he strongly criticised Moscow [Soviet Union] and was expelled from the Czech Communist Party as a "Trockyist" ….. agent of the Bourgeoisie". In 1931 Vilim joined the Social Democratic Youth Movement, also becoming secretary of the Metal Workers Union and editor of the Union's magazine. In 1934 he met Mirka Panova, secretary of the district branch of the Social Democratic Womens' Movement, and in 1938 they were married.

As a prominent Trade Unionist, Vilim was arrested in 1940 by the Gestapo and spent 6 months as their prisoner in Prague. He was then transferred to police custody in Berlin [Germany] and sentenced at a show trial presided over by Hitler's Minister of Justice, to Ebrach Prison in Bavaria. Vilim remained first in Ebrach and then Bamberg from 1940 to 1945; he was then freed by the United States Army. Vilim served his sentence with the Communist Jiri Hajek, later Ambassador in London and subsequently Czechoslovak Foreign Minister.

In 1947 Vilim was instrumental in defeating the Communist wing at the Brno Conference of the Social Democratic Party, for which the Communists never forgave him. He fled from Czechoslovakia [later Czech Republic and Slovakia] n 1948 to West Germany [later part of Germany] and spread warning to Western Socialists not to enter into any coalitions with Communists within their own countries. In the same year, he attended the Committee of the Socialist International held in Transport House, London, at the invitation of Denis Healey. Vilim then took on a factory job and returned to his original craft of chased metal work at which he worked until the age of 62, but in 1971 returned to political work in the form of journalism. Vilim founded the independent quarterly journal Perspektivy Socialismu to discuss key questions of current socialism.

In 1976 Vilim died of a heart attack at the age of 67. His wife Mirka Vilim committed suicide on 19 August 1977.