Born in the Volhynian village of Przebraże, he worked as a forester, when in September 1939 the Red Army invaded eastern Poland.
Upon coming back, he took up several menial jobs, trying to lie low and not to attract attention of Soviet authorities.
In early spring of 1943, at the beginning of Massacres of Poles in Volhynia by the Ukrainian Insurgent Army (UPA), he became one of the commandants of the Przebraże Defence together with Ludwik Malinowski.
Under his leadership, Polish resistance groups reorganised into a 500-man-strong brigade, including a cavalry unit.
In 1969 Cybulski issued a book Czerwone noce ("Red nights"), worked out by Henryk Pająk, based on his memoirs, in which he described Ukrainian massacres of Poles in early 1940s Volhynia.