Long partitioned between the Russian, Austrian and German empires (1795-1918), Poland recovered its independence on 11 November 1918. Its baseline borders were recognized by the League of Nations (LN) in 1923, in the aftermath of several military campaigns. A territory of plains stretching 389,000 square kilometers, it was bounded in the west by the districts of Katowice, Poznań and Toruń, with access to the Baltic Sea near the free city of Danzig (Gdańsk), and in the east by Wilno (Vilnius), Tarnopol and Stanislawów. The new state adopted a parliamentary democratic constitution in 1921. At that time, it had a population of 31.9 million, including various minorities – Ukrainians 14.3 per cent, Jews 7.8 per cent, Belorussians 3.9 per cent and Germans 3.9 per cent – all of whom were Polish citizens (Glowny Urzad Statystyczny, 2003: 382).
For 30 years in the first half of the twentieth century, the country experienced several waves of violence, which varied greatly in scale. For the first twenty years, and in the immediate post-war period, political and inter-minority tensions resulted in a climate of insecurity for large swathes of the population and led to civilian casualties during armed clashes. On the other hand, mass violence reached unprecedented proportions during the war (1939-1945), which for Poland ended in the loss of more than 17 per cent of its civilian population (including 90 per cent of Polish Jews). Decided during the Allied conferences at Yalta and Potsdam (1945), boundary changes and transfers of German, Ukrainian and Polish populations fashioned a mono-ethnic society from 1948 onwards. The waves of violence were spread over four periods:
I. Tensions and violence against minorities (1918-1939)
II. Nazi terror and Stalinist repression (1939-1941)
III. Extermination of the Jews and racial purification of the territory (1941-1945).
IV. Seizure of power by the communists (1945-1948).