[3] Born into a wealthy, enlightened Jewish family, his mother was Berta Eisenstädt and his father was Zsigmond Klein, a store manager who settled in Nagybocskó at the end of the 19th century.

In the early 1910s, he met Zoltán Franyó, art historian Hugó Kenczler, and Tibor Szamuely.

After the outbreak of World War I, Klein enlisted as a soldier, but was able to leave his military service because of his spine problems.

As the department head of the capital bank Fabank, he joined the left-wing group of the National Association of Financial Institution Officials and also attended the lectures of Ervin Szabó at the Galileo Circle.

After the arrest of the Galilean leaders in January 1918, an illegal antimilitarist movement that was composed of revolutionary socialists continued to exist.

After the proclamation of the Soviet Republic, he first became the head of the commercial department of the Socialist Production Committee and issued a decree on the socialization of shops (meaning: nationalization and confiscation).

His companion was Imre Sallai [hu], his deputies were Ferenc Stein, János Guzi and Károly Benyovszky.

The Budapest Revolutionary Court sentenced many people to death on the instructions of Korvin and Jenő László for a crime of counter-revolutionary behavior.

In mid-May 1919, after disarming the Chernig group, 43 people were assigned under Corvary's command in the Political Investigation Department.

Lukács later stated that he suspected Béla Kun had intentionally chosen them in the conviction that they would both be killed and "martyred".

4039/1919[clarification needed] on the basis of an expedited criminal prosecution procedure regulated by decree, before the advice of Judge Gyula Surgoth.