Ukrainian Social Democratic party (Українська соціал-демократична партія; Ukrainska sotsiial-demokratychna partiia, or УСДП; USDP). A socialist workers' party founded on 18 September 1899 by Ukrainian members of the Polish Social Democratic Party of Galicia and Silesia (PPSD) who had formed a Ukrainian social democratic organization in Lviv in 1897, and by a minority faction that split away from the Ukrainian Radical party. The USDP was a national section of the federated Social Democratic Party of Austria. Its Austro-Marxist program advocated the equality and autonomy of all nations in the Austro-Hungarian and Russian empires and the creation of a pan-Ukrainian independent republic. The executive consisted of Yuliian Bachynsky, Mykola Hankevych (the chairman), Roman Yarosevych (a member of the Austrian State Council), Mykhailo Novakovsky, and Semen Vityk. Hankevych and Vityk were the key leaders. Other prominent members were Roman Dombchevsky, Ye. Kosevych, Volodymyr Levynsky, Teofil Melen, P. and Stepan Novakovsky, M. Ogrodnik, Yatsko Ostapchuk, Myroslav Sichynsky, Ivan Siiak, Dariia Starosolska, M. Vitoshynsky, and Ivan Vozniak. The USDP had ties with the Revolutionary Ukrainian party and Ukrainian Social Democratic Workers' party in Russian-ruled Ukraine. By concentrating on trade-union work among the Ukrainian rural proletariat and organizing strike committees during the 1902 peasant strikes in Galicia and Bukovyna it fostered a national identity and class consciousness within the Ukrainian peasantry. The first USDP congress was held in Lviv in March 1903. A fraternal Ukrainian section of the Social Democratic Party of Bukovyna was founded in 1906 and was led by Yosyp Bezpalko.

Until 1907 the USDP was de facto a section within the PPSD. Its leaders Semen Vityk and Mykola Hankevych were also members of that party (Hankevych headed the PPSD committee in Lviv). By mutual agreement the USDP did political work in the Galician Ukrainian villages, and the PPSD was active in urban centers. In 1906, however, Levynsky and other younger USDP members began demanding that the USDP do political work among the Ukrainian urban proletariat independently of the PPSD. Consequently, at the June 1907 USDP conference a new party statute was adopted, which made the USDP independent of the PPSD and instructed its members to begin organizing USDP committees, Volia workers' associations (see Volia society), and Ukrainian trade unions in urban centers; it also postulated the ethnic partitioning of Galicia. During the 1907 elections to the Austrian parliament the USDP received 8 percent of the Ukrainian vote and sent Yatsko Ostapchuk and Vityk to the Chamber of Deputies. At the December 1911 USDP conference factional strife between the pro-PPSD leadership and the independentist ‘young’ faction (Yuliian Bachynsky, Porfyr Buniak, Lev Hankevych, Ivan Kvasnytsia, Volodymyr Levynsky, Volodymyr Starosolsky, Volodymyr Temnytsky, Roman Yarosevych) ended in the secession of the latter group. The USDP was not reunited until its fifth congress, in March 1914, which elected Temnytsky the new leader.

During the First World War USDP members were active in nation-building organizations such as the Supreme Ukrainian Council and the General Ukrainian Council, the Combat Board of the Ukrainian Sich Riflemen, and the Union for the Liberation of Ukraine. In 1918 they took part in the first Ukrainian National Rada of the Western Ukrainian National Republic (ZUNR). Semen Vityk was one of the Ukrainian National Rada presidium's vice-presidents and a member of the executive; O. Ustyianovych was the presidium's deputy secretary; and Volodymyr Birchak, M. Boikovych, Antin Chernetsky (also the first ZUNR state secretary of labor and social security), Lev Hankevych, Mykola Hankevych, Ivan Kalynovych, Y. Krupa, R. Kulytsky, I. Liskovatsky, H. Mariiash, and R. Skybinsky were Ukrainian National Rada delegates. As early as December 1918, however, the USDP left the coalition government and joined the socialist opposition, the Peasants' and Workers' Union. The USDP supported the January 1919 unification of the ZUNR and the Ukrainian National Republic, however, and from April 1919 to May 1920 Yosyp Bezpalko, Volodymyr Temnytsky, and Vityk held portfolios in the Council of National Ministers of the Ukrainian National Republic. Volodymyr Starosolsky served as a deputy minister.

In 1921, after the Soviet-Polish Peace Treaty of Riga partitioned Ukraine between the two powers and the Army of the Ukrainian National Republic was routed in the Ukrainian-Soviet War, 1917–21, the USDP adopted a pro-Soviet Ukrainian-unification platform and remained openly hostile to both the Polish government and Yevhen Petrushevych's Vienna-based ZUNR government-in-exile. In the early 1920s members of the Communist Party of Western Ukraine (KPZU) led by Osyp Vasylkiv infiltrated the USDP upper echelons. Consequently, at its sixth congress, in Lviv in March 1923, the USDP adopted a Communist platform and removed Mykola Hankevych, Lev Hankevych, R. Skybinsky, Volodymyr Starosolsky, Porfyr Buniak, and Ivan Kvasnytsia from the leadership. In 1922 the Volhynian USDP members A. Bratun, M. Chuchmai, Serhii Kozytsky, Marko Lutskevych, V. Mokhniuk, Andrii Pashchuk, Khoma Prystupa, Yosyp Skrypa, Pavlo Vasynchuk, and Yakiv Voitiuk were elected to the Polish Sejm. In November 1923 they met in Lutsk with other representatives of Ukrainian socialist organizations and established a united front, which was named the USDP of Eastern Galicia, Volhynia, the Kholm Region, Polisia, and Podlachia in December.

On 30 January 1924 the Polish government proclaimed the USDP a threat to peace and order and outlawed it and its organs. Most USDP members then joined the underground Communist Party of Western Ukraine. The Sejm members Mokhniuk, Andrii Pashchuk, Khoma Prystupa, Yosyp Skrypa, and Yakiv Voitiuk left the Ukrainian Parliamentary Representation, formed their own Ukrainian Social Democratic Club, and then in November joined the Communist caucus in the Sejm. The non-Communist USDP minority became involved in the Robitnycha Hromada cultural and educational society. Lev Hankevych's Vpered group revived the USDP in 1928. Under his and, from 1933, Volodymyr Starosolsky's leadership the new USDP belonged to the Labor and Socialist International. In December 1934 it formed a Ukrainian Socialist Bloc with the Ukrainian National Democratic Alliance and the Ukrainian Socialist Radical party. By that time the USDP had few members and little political influence or support, and after the German invasion of Galicia in 1939, it became inactive. Postwar émigrés in Western Europe who had been USDP members helped to found the Ukrainian Socialist party.

The USDP organs were Volia (Lviv) (1900–7), Zemlia i volia (1906–13, 1919–20, 1922–4), Chervonyi prapor (Ternopil) (1906–7), Nash holos (Lviv) (1910–11), Vpered (Lviv) (1911–13, 1918–24), Pratsia (1914, 1918), and, in Bukovyna, Borba (1908–14, 1918), Volia naroda (1919–21), Robitnyk (1919–23), and Borot’ba (1925–8).

BIBLIOGRAPHY
Levyns’kyi, V. Narys rozvytku ukraïns’koho robitnychoho rukhu v Halychyni (Kyiv 1914; rev edn, 1930)
———. Narys istoriï Ukraïns’koï sotsiial-demokratychnoï partiï (Lviv 1921)
Papierzyńska-Turek, M. Sprawa ukraińska w Drugiej Rzeczypospolitej 1922–1926 (Cracow 1979)
Petliura, S. ‘Politychni ukraïns’ki partiï v Halychyni: 1. Ukraïns’ka partiia sotsiial-demokratychna,’ in Symon Petliura: Statti, lysty, dokumenty, 2 (New York 1979)
Hornowa, E. ‘Powstanie Ukraińskiej Partii Socjalno-Demokratycznej w Galicji Wschodniej,’ Zeszyty Naukowe Wyższej Szkoły Pedagogicznej im. Powstańcow Śląskich w Opolu: Historia, 17 (1980)

Roman Senkus

[This article originally appeared in the Encyclopedia of Ukraine, vol. 5 (1993).]