From its creation until September 1940, the CML was led by Gheorghe Clime; afterwards, the position was filled by Dumitru Groza, who oversaw the Corps during the period when the Iron Guard was in power — the National Legionary State —, and involved it in the 1941 Rebellion and Pogrom.
As early as 1919, he had joined Constantin Pancu in his Garda Conştiinţei Naţionale, an association of workers, engaging in street battles with those whom they saw as Bolshevik agitators and drafting a political program which owed inspiration to the Austrian Christian Social Party and, possibly, to the DNSAP.
[5] The Corps, coinciding with a peak in Iron Guard popularity and influence,[3][5] as well as with the apex of interwar industrialization in Romania,[3] signified a major shift in regard to recruitment policies.
[4][6] There are several views in respect to its overall importance inside the larger movement: according to Aurel Dragoş Munteanu, the Corps was the largest and most popular branch,[4] while Francisco Veiga describes it as "an elite organization", and argues that its strength lay in determination rather than sheer numbers.
[3] Following King Carol II's 1938 decision to monopolize stately power and the subsequent creation of the National Renaissance Front as the single ruling party, the CML remained active in the underground, but was much weakened and efficiently supervised by the secret police (Siguranţa Statului).
[9] In the process, the CML and Ajutorul Legionar, the Guard's humanitarian venture, were depicted as evidence that the Sima's was the only political body capable of dealing with the social problems faced by soldiers.
[9] In parallel, the CML's paramilitary troops took part in waves of violence and repression, occasionally taking initiative; on November 26–27, 1940, together with Legionary sympathizers in the Romanian Police, it carried out the killings of former National Renaissance Front officials who were detained in Jilava.
[10] In 1945, following Antonescu's downfall and the onset of Soviet occupation (see Romania during World War II), and the establishment of the Petru Groza executive, state authorities progressively came under control from the Romanian Communist Party.
In the process, the factionalized and underground interior branch of the Iron Guard was approached by the Communist Party's Teohari Georgescu and Alexandru Nicolschi with an offer for a truce (evidence was also cited that the agreement was directly ordered by Soviet overseers).