Born in Miculești, Gorj County. After attending the Artillery Military School in Bucharest (1908–1910), he graduated with the rank of second lieutenant, advancing to lieutenant in 1913, and to captain in 1916. He commanded in World War I the 5th Artillery Regiment, fighting in the Romanian Campaign at the battles of the Jiu Valley and Dragoslavele. In 1917 he was promoted to major, and was awarded the Order of the Crown, knight rank. Subsequently, he fought in the Campaign of 1917, at the battles of Mărășești and Oituz. After the war, Carlaonț pursued his studies at the Higher War School (1919–1920), after which he was promoted to lieutenant colonel in 1927, to colonel in 1934, and to brigadier general in 1939.