Heroes’ Day is an unofficial holiday observed in Ukraine every May 23, primarily celebrated in the western regions of the country. This day honors all Ukrainians who have sacrificed their lives for the freedom and independence of Ukraine throughout its history, from Kyivan Rus to the present-day conflict with Russia. The holiday was established in 1941 by the Organization of Ukrainian Nationalists (OUN) to commemorate its first leader, Yevhen Konovalets, who was assassinated on this date in 1938. The choice of May also pays tribute to other prominent figures in Ukrainian nationalism who died in May, including Mykola Mikhnovsky and Symon Petliura. Although not a public holiday, Heroes’ Day has gained popularity since Ukraine's independence in 1992, especially after 2014, with local governments organizing events such as rallies, parades, and solemn remembrance ceremonies to honor fallen heroes. The observance is closely associated with nationalist organizations and includes recognition of various historical groups and movements that fought for Ukraine's independence.