Answer by taking a quote from the following article:

Corneliu Zelea Codreanu (Romanian pronunciation: [kor'neliu 'zelea ko'dreanu] ( listen); born Corneliu Zelinski; September 13, 1899 - November 30, 1938), commonly known as Corneliu Codreanu, was a Romanian politician who was the founder and charismatic leader of the Iron Guard (also known as the Legionnaire movement), an ultranationalistic and antisemitic organization active throughout most of the interwar period. Generally seen as the main variety of local fascism, and noted for its Romanian Orthodox-inspired revolutionary message, the Iron Guard grew into an important actor on the Romanian political stage, coming into conflict with the political establishment and democratic forces, and often resorted to terrorism. The Legionnaires traditionally referred to Codreanu as Capitanul ("The Captain"), and he held absolute authority over the organization until his death. Codreanu, who began his career in the wake of World War I as an anticommunist and antisemitic agitator associated with A. C. Cuza and Constantin Pancu, was a co-founder of the National-Christian Defense League and assassin of the Iasi Police prefect Constantin Manciu.

Codreanu felt he had to amend the purpose of the movement after more than two years of stagnation: he and the leadership of the movement started touring rural regions, addressing the churchgoing illiterate population with the rhetoric of sermons, dressing up in long white mantles and instigating Christian prejudice against Judaism (this intense campaign was also prompted by the fact that the Legion was immediately sidelined by Cuza's League in the traditional Moldavian and Bukovinan centers). Between 1928 and 1930, the Alexandru Vaida-Voevod National Peasants' Party cabinet gave tacit assistance to the Guard, but Iuliu Maniu (representing the same party) clamped down on the Legion after July 1930. This came after the latter had tried to provoke a wave of pogroms in Maramures and Bessarabia. In one notable incident of 1930, Legionaries encouraged the peasant population of Borsa to attack the town's 4,000 Jews. The Legion had also attempted to assassinate government officials and journalists -- including Constantin Angelescu, undersecretary of Internal Affairs. Codreanu was briefly arrested together with the would-be assassin Gheorghe Beza: both were tried and acquitted. Nevertheless, the wave of violence and a planned march into Bessarabia signalled the outlawing of the party by Premier Gheorghe Mironescu and Minister of the Interior Ion Mihalache (January 1931); again arrested, Codreanu was acquitted in late February.  Having been boosted by the Great Depression and the malcontent it engendered, in 1931, the Legion also profited from the disagreement between King Carol II and the National Peasants' Party, which brought a cabinet formed around Nicolae Iorga. Codreanu was consequently elected to Chamber of Deputies on the lists of the Corneliu Zelea Codreanu Grouping (the provisional name for the Guard), together with other prominent members of his original movement -- including Ion Zelea, his father, and Mihai Stelescu, a young activist who ultimately came into conflict with the Legion; it is likely that the new Vaida-Voevod cabinet gave tacit support to the Group in subsequent partial elections. The Legion had won five seats in all, which was its first important electoral gain.  He quickly became noted for exposing corruption of ministers and other politicians on a case-by-case basis (although several of his political adversaries at the time described him as bland and incompetent).

What happen in the first outlaw and parliamentary mandate?
Codreanu felt he had to amend the purpose of the movement after more than two years of stagnation: he and the leadership of the movement started touring rural regions,