The History of Lemberg (Lviv, Lwów, Lvov) prior to World War I
Lemberg was founded by the Ruthenian duke Danylo Romanovič (1201-1264) around 1250 and soon became an important political, cultural and trade center, under Polish rule from 1387 on. In 1772, in the wake of the first partition of Poland, the city was annexed by the Habsburg monarchy and became the capital of the Austrian crownland Galicia and Lodomeria. Around 1900 Lemberg had about 160,000 inhabitants. 49.4 percent were Polish, 26.5 percent were Jews and 19.9 percent were Ruthenians/Ukrainians. The Polish élites had considerable political power within the local government and were in possession of much of Galicia’s land. The emergence of Ukrainian nationalism led to the foundation of a national party in 1899 which aimed at national unity and independence. Therefore, on the eve of World War I, the situation in Lemberg was characterized by growing nationalism and antisemitism and a conflict between Poles and Ukrainians on the verge of escalation.
At the outbreak of the war Lemberg – together with Cracow and Przemyśl – was one of the biggest garrisons of the Austro-Hungarian army in the east and was of great strategic importance. It was a cornerstone in the protection of Austria-Hungary against Russia. After the first defeats of Austro-Hungarian troops, civil and military authorities began a wave of persecutions against Russophile Ukrainians for alleged treason. This led to the arrest of members of the National Party and many alleged pro-Russian politicians.
...
The Polish-Ukrainian War
When the Habsburg monarchy collapsed, an open conflict broke out between the Poles and the Ukrainians over the possession of Galicia. On 1 November 1918 the Western Ukrainian National Republic was proclaimed. However, after heavy fighting, the Poles forced the Ukrainians out of the city by 21 November 1918. In the following unrests from 22 to 24 November, a large number of Jewish citizens was killed or injured, their houses (as well as those of Ukrainians) were looted and burnt down. Despite mediation attempts by the Entente Powers, the war continued until July 1919. The Treaty of Warsaw, signed on 21 April 1920, finally ended the hostilities between the Polish Republic and the Ukrainian People’s Republic, recognizing recent Polish territorial gains in western Ukraine and the border along the Zbruch River.
https://encyclopedia.1914-1918-online.net/article/lemberg
Eastern Galicia and Volhynia were inhabited by Ukrainians, Poles, and Jews for centuries. Although Ukrainians made up the majority of the population in these two regions, they were less present in cities such as Lviv than in villages and small towns. Before the Second World War, Jews made up in both regions about 10 percent of all inhabitants, Poles about 25 percent in eastern Galicia and 15 percent in Volhynia, and Ukrainians 60 percent in eastern Galicia and 70 percent in Volhynia.2 As a result of the first and second partitions of the Polish-Lithuanian Commonwealth in 1772 and 1793, eastern Galicia was incorporated into the Habsburg Empire and Volhynia into the Russian Empire, that also held the south, central, and eastern Ukrainian territories and regarded them as parts of Russia. This geopolitical order changed only after the First World War. In November 1917, Ukrainians proclaimed a state in Kiev and in November 1918 in Lviv, but they did not succeed in keeping either of them. In 1921, eastern Galicia and Volhynia were officially incorporated into the Second Polish Republic, and almost all other Ukrainian territories constituted the Ukrainian Soviet Socialist Republic.3
https://journals.sagepub.com/doi/10.1177/0888325419831351