Original sentence: During the interwar period of the 20th century (1920-1939) Lithuania-Polish relations were quite bad.Further Polonisation was ensued as the government encouraged settlement of Polish army veterans in disputed regions.Lithuanian minority in Poland was an object of Polonisation, as almost all Lithuanian schools were closed (closed 266, only 3 remained) and almost all organizations were banned.Starting with the conflict over the city of Vilnius (Wilno), and the Polish-Lithuanian War shortly after the First World War, both governments - in the era nationalism was sweeping through Europe - treated their respective minorities harshly
Edited sentence: During the interwar period of the 20th century (1920-1939)  Lithuanian - Polish relations were quite bad, and Lithuanian minority in Poland was an object of aggressive Polonisation, especialy in fourth decade, as almost all Lithuanian schools were closed (closed 266, remained only 3) and all organizations were banned.Further Polonisation was ensued colonising lands inhabited by Lithuanians with Polish army veterans