Between 1902 and 1905, Ivan Lorković was the editor of the Osijek opposition newspaper, National Defense (Croatian: Narodna Obrana).

[citation needed] In 1914, Lorković visited Rome to attend a meeting that included politicians from all South Slavic lands within the Monarchy.

[citation needed] His proposal was met with opposition, most notably from Thomas G. Masaryk (founder and first president of the State of Czechoslovakia), who was skeptical of the plan since he did not believe that Britain and France would accept the idea of the total abrogation of the Empire, and was therefore in favor of a confederation.

[3] In 1918, due to disagreements over the Yugoslav issue, Lorković left the Croatia-Serb coalition and joined the newly founded Croatian Union political party in 1919.

[6] Ivan's father was Blaž Lorković, a prominent economist and lawyer who is often credited with the development of the Croatian political economy.