Julian Sas-Kuilovsky was born on May 1, 1826, in the village of , in Sambir Raion, Lviv Oblast, Ukraine to a family of nobles. He studied philosophy in the Lviv University which expelled him due his participation to the revolutionary risings which led to the revolution of 1848. After the defeats in 1848, he followed as sotnik (Captain) the general Józef Bem in his revolutionary campaign till the final defeat of the Battle of Segesvár.