Before the outbreak of the World War I, Gagliardi was a member of the Party of Rights in the Kingdom of Croatia-Slavonia, then a part of Austria-Hungary.
In December 1918, following the dissolution of Austria-Hungary and establishment of the Kingdom of Serbs, Croats and Slovenes (renamed Yugoslavia in 1929), Gagliardi moved to Graz, Republic of German-Austria.
The organisation, led by Ivo Frank advocated Croatian independence from the Kingdom of Serbs, Croats and Slovenes.
Gagliardi returned to the Kingdom of Serbs, Croats and Slovenes in 1923, and was briefly arrested in Zagreb.
He was arrested along with other suspected free masons and imprisoned in the Stara Gradiška concentration camp.