After graduating from high school, Ștefan Davidescu became a student at the Textile Faculty, Polytechnic University, Bucharest. The gradual seizure of power by the communists led him to join the National-Peasant Youth, the student organization of the party led by Iuliu Maniu.

Of all the measures taken by the new communist government in Bucharest, the one which angered him the most was King Mihai's forced abdication and the replacement of the monarchy as a form of government with the republic.

The moment that would change his life forever happened in December 1948, when his friend Mihai Vintilescu called him to a party. Enjoying fresh wine, Ștefan, together with Theodor (Dory) Davidescu, his cousin, Mihai Vintilescu and Ion Brătilă, retreated to a corner. All four had similar anti-communist and monarchic views. As a year had passed since the forced abdication of the King, the young people express their desire to start their own fight against communism and decide to print manifests to be distributed on the streets of Ploiești and in some university centers in the country. Their symbol would be the letter E (from Liberation – Eliberare in Romanian) stamped in the upper right corner of each manifesto.

And so, Mihai, Ștefan, Dory and Ion distributed a few hundred manifestos one night at the end of December 1948. Understanding that their gesture could not escape the watchful eye of the Securitate, each sought to flee or hide: after an unsuccessful attempt to cross the border westward, Ștefan hid in the house of peasant party members acquaintances in Bucharest. He managed to escape arrest, but his mother and brother George were detained for three months and investigated by the Securitate, just like the families of his colleagues.