Born in Bucharest, he lived for part of his childhood at the family manor in Botoșani, where, at age 11, he witnessed first-hand the 1907 peasants' uprisings (which, as he later admitted, contributed to his left-wing sympathies).
[3] After his return to Romania, Callimachi edited a short-lived magazine in Botoşani (1924–1925),[4] and published Avant-garde poems in free verse — inspired by the work of Russian Futurists.
[6] He began working on communist and other leftist newspapers (including Clopotul, which he himself edited in his native town) while keeping a front as an employee of his relatives.
[3] He continued to criticize the PNȚ: the most virulent of his attacks on the cabinet of Alexandru Vaida-Voevod — voiced soon after the authorities had repressed the Grivița strike of 1933 — led to his arrest and sentencing.
[3] Like Pătrășcanu, Callimachi was set free by Siguranța Statului under the National Legionary State, established by the Iron Guard later in the year (the regime, which had aligned itself with Nazi Germany, was attempting to preserve a good relationship with the Soviet Union).