regional differences existed. During the 18th century, the regions began to catch up with western Europe, but did not develop as rapidly. Areas with stronger female autonomy developed more quickly in terms of numeracy. Serfdom Serfdom was a prevalent status of agricultural workers until the 19th century. It resembled slavery in terms of lack of freedom, however the landowners could not buy and sell serfs, who are permanently attached to specific plots of land. The system emerged in the 14th and 15th century, the same time it was declining in Western Europe. The climax came in the 17th and 18th century. The early 19th century saw its decline, marked especially by the abolition of serfdom in Russia in 1861. Emancipation meant that the ex-serfs paid for their freedom with annual cash payments to their former masters for decades. The system varied widely country by country, and was not as standardized as in Western Europe. Historians, until the 20th century, focused on master-serf economic and labor relations, portraying the serfs as slave-like, passive, and isolated. 20th century scholars downplayed the evils and emphasize the complexities. Interwar period (1919–1939) A major result of the First World War was the breakup of the Russian, Austro-Hungarian, and Ottoman empires, as well as partial losses to the German Empire. A surge of ethnic nationalism created a series of new states in Eastern Europe, validated by the Versailles Treaty of 1919. Poland was reconstituted after the partitions of the 1790s had divided it between Germany, Austria, and Russia. New countries included Finland, Estonia, Latvia, Lithuania, Ukraine (which was soon absorbed by the Soviet Union), Czechoslovakia, and Yugoslavia. Austria and Hungary had much-reduced boundaries. The new states included sizeable ethnic minorities, which were to be protected according to the League of Nations minority protection regime. Throughout Eastern Europe, ethnic Germans constituted by far the largest single ethnic minority. In some areas, as in the Sudetenland, regions of Poland, and in parts of Slovenia, German speakers constituted the local majority, creating upheaval regarding demands of self-determination. Romania, Bulgaria, and Albania likewise were independent. Many of the countries were still largely rural, with little industry and only a few urban centres. Nationalism was the dominant force but most of the countries had ethnic or religious minorities who felt threatened by majority elements. Nearly all became democratic in the 1920s, but all of them (except Czechoslovakia and Finland) gave up