Born in Székelyudvarhely, the ninth of eleven children in a family of Transylvanian Saxons, his ties to Communism began at an early age when he became a member of the Communist Party of Hungary (KMP).

He was to be executed, and was transported to the prison of Sopronkőhida, then into Germany; but the intercession of his elder brother, Endre, a fascist under-secretary, saved his life.

Under the cover of "struggle against fascism and reaction" and "defence of the power of proletariat", he prohibited and liquidated several religious, nationalist, and maverick establishments and groups (the number of these was about 1,500), and set up the first show trials.

László Rajk was accused of being a "Titoist Spy", an agent for western imperialism and one who planned on restoring capitalism and jeopardizing Hungary's independence.

Stalin's NKVD emissary coordinated with Hungarian General Secretary Mátyás Rákosi and his ÁVH to orchestrate Rajk's show trial.

[3] At his trial, held between 16 and 24 September 1949,[2] in the large assembly hall of the headquarters of the Metal and Engineering Workers' Trade Union in Budapest, he confessed to all the charges brought against him.

On 28 March 1956, following numerous demonstrations, Rajk was rehabilitated in spite of his responsibility for the excesses of the secret police ÁVH which he had founded in 1946, including initial large purges and executions under his direction.

[citation needed][5] László Rajk: the events of his political and family life, beginning circa 1945, his trial, execution, reburial, atonement, and ending with the Hungarian Revolution of 1956 and the USSR's armed invasion of Hungary, are all portrayed in Robert Ardrey's 1958 play, Shadow of Heroes.