Brlić took part in the Revolution of 1848, and in March he left theology. In June, he was at the Prague barricades, in September he was in Jelačić's campaign against Hungary, then his envoy to the Czech revolutionary leaders with whom they agreed on Czech-Slavic cooperation in the process of reorganization of the Habsburg Monarchy. In December, Jelačić sent him as emissary to France to the newly elected President of the Second Republic, Louis Bonaparte, for consultations on the revolutionary situation in Europe and possible French plans. France, burdened by its own revolution, had no foreign policy plans. As Brlić's mission was fruitless, Jelačić cut his funding, so Brlić relied on Ilija Garašanin, Interior Minister of Serbia in order to stay in Paris.