The Organization of Ukrainian Nationalists was formed in Vienna in 1929. OUN emerged from a merger of several nationalist organizations – the Ukrainian Military Organization, the League of Ukrainian Nationalists – and several nationalist student associations. At its founding conference from 28 January-3 February 1929, it elected a nine-man Leadership of Ukrainian Nationalists, with Colonel Yevhen Konovalets as its head.

The goal of OUN was to establish an independent national Ukrainian state on Ukrainian ethnic territories through revolutionary means. Collaboration of any kind with regimes occupying Ukrainian territories was eschewed. Violence was accepted as a political tool against all enemies of the cause. In the 1930s the activity of OUN was concentrated mainly in Galicia and Volyn against the Polish regime. OUN carried out sabotage against Polish landowners, led boycotts of state schools, and of Polish alcohol and tobacco monopolies. OUN also attacked government institutions and carried out dozens of assassinations.

The Polish regime reacted to these attacks with a campaign of pacification, begun in 1930. Throughout the 1930s many members of OUN were imprisoned, and in 1934 many of OUN’s leaders, including the head of the Western Ukrainian Territorial Executive Stepan Bandera, were arrested and kept in prison until the outbreak of WWII. OUN did not succeed in penetrating Soviet Ukrainian territory; however, concerned with the potential of OUN, Stalin ordered the assassination of Konovalets in 1938.

The OUN membership consisted mostly of young people and students. Some estimates put the membership of OUN in the 1930s in Galicia and Volyn as high as 20 000. OUN’s influence, however, was much greater than the size of its membership may suggest. As the leading Ukrainian nationalist organization, OUN embodied Ukrainian desires for independence and was the key organization in shaping the political attitudes of Western Ukrainians.

The assassination of Konovalets led to a succession crisis in OUN. At the 2nd Grand Assembly of OUN in Rome in August 1939 Andriy Melnyk was elected leader. After the occupation of Poland by German forces, Bandera and other young leaders emerged from prison, and challenged Melnyk’s leadership and accused him of abandoning the principles on which OUN had been founded in 1929. In February 1940 the faction led by Bandera formed the Revolutionary Leadership and in April 1941 held an Extraordinary Congress in Krakow, at which it declared Melnyk’s leadership illegal and elected Bandera as the head of OUN. OUN thus split into two separate factions – OUN-Melnyk, which was the moderate wing, and OUN-Bandera, which was the revolutionary wing. Most of the OUN cadres operating on Ukrainian territory accepted Bandera’s leadership, while most of OUN cadres living abroad continued to stay loyal to Melnyk.

Both wings of OUN saw the coming war between Germany and the USSR as an opportunity for the establishment of an independent Ukrainian state. As such both sides cooperated with German authorities. The line of reasoning was that Germany would undoubtedly need Ukrainian help in its war against the USSR; Germany would thus have to accept an independent Ukrainian state. On 30 June 1941 OUN-B proclaimed Ukrainian independence in Lviv, with Yaroslav Stetsko as premier. Hitler reacted to this declaration by ordering the arrest of Bandera and many of his associates. Bandera spent the rest of the war in a German concentration camp, and many members of OUN-B were executed or sent to concentration camps. Many members of OUN-M met the same fate; Melnyk was kept under house arrest in Berlin until 1944, when he was imprisoned in a concentration camp.

After the arrest of Bandera and Melnyk resistance to German rule began with the establishment of the Polisian Sich under Taras Borovets, which cooperated with OUN-M. The Ukrainian Insurgent Army (UPA) was formed in 1943, under the leadership of OUN-B, and absorbed most of the other nationalist Ukrainian formations operating in Ukraine. At its Third Extraordinary Congress in August 1943, OUN-B condemned both fascist national-socialism and Russian Bolshevism, and adopted a nationality policy that was based on rights for national minorities, replacing its previous stand of “Ukraine for Ukrainians.” OUN-B also modified its command structure, replacing one-man rule with a three-man leadership Bureau of R. Shukhevych, Z. Matla, and D Maivsky. In July 1944 the Ukrainian Supreme Liberation Council was set up, consisting mostly of members of OUN-B and led by Shukhevych.

After the War, strife between the two factions of OUN continued as they struggled for dominance first in the Displaced Persons’ camps, and later, in the Ukrainian diaspora. However, both OUN-M and OUN-B at its core represented the Ukrainian struggle against imperialism and the desire for an independent Ukrainian state. In Ukraine, the work of OUN was not forgotten, particularly in Western Ukraine, and despite years of Soviet occupation the dream for a free Ukraine was never stamped out.