Armand Călinescu, the then Prime Minister of Romania, was assassinated on 21 September 1939, aged 46, in Bucharest by Iron Guard members under the direct leadership of Horia Sima (exiled in Steglitz at the time).

[5][6] According to historian Armin Heinen [de], the Legionary leadership exiled in Germany in 1938 received support from Alfred Rosenberg's NSDAP Office of Foreign Affairs, and possible SD backing for the assassination of Călinescu.

[7][8]: 681  On 1 September 1939, representatives of Germany, Fascist Italy, and the Iron Guard met in Copenhagen with Mihail R. Sturdza (Romania's ambassador to Denmark and a supporter of Sima), to discuss Călinescu's killing.

[13][14] Sima, who is known to have crossed the border illegally in August of that year,[15][10] was alleged to have disguised himself as a woman in order to witness the actions from nearby;[15] other sources indicate a certain Marin Stănculescu as the covert supervisor.

[22] Mass executions of known Iron Guard activists were ordered in various places in the country (some were hanged on telegraph poles, while a group of Legionnaires was shot in front of Ion G. Duca's statue in Ploiești).

[20] Călinescu's wife Adela was required to hand all of her husband's personal documents and, in a letter to Conducător Ion Antonescu, claimed to have been repeatedly harassed by agents of Siguranța Statului.