of Bulgaria was Romaniote until the 14th to 15th centuries, when Ashkenazim from Hungary (1376) and other parts of Europe began to arrive. Ottoman rule By the completion of the Ottoman conquest of the Bulgarian Empire (1396), there were sizable Jewish communities in Vidin, Nikopol, Silistra, Pleven, Sofia, Yambol, Plovdiv (Philippopolis) and Stara Zagora. In 1470, Ashkenazim banished from Bavaria arrived, and contemporary travellers remarked that Yiddish could often be heard in Sofia. An Ashkenazi prayer book was printed in Saloniki by the rabbi of Sofia in the middle of the 16th century. Beginning in 1494, Sephardic exiles from Spain migrated to Bulgaria via Salonika, Macedonia, Italy, Ragusa, and Bosnia. They settled in pre-existing Jewish population-centres, which were also the major trade centres of Ottoman-ruled Bulgaria. At this point, Sofia was host to three separate Jewish communities: Romaniotes, Ashkenazim and Sephardim. This would continue until 1640, when a single rabbi was appointed for all three groups. In the 17th century, the ideas of Sabbatai Zevi became popular in Bulgaria, and supporters of his movement, such as Nathan of Gaza and Samuel Primo, were active in Sofia. Jews continued to settle in various parts of the country (including in new trade centres such as Pazardzhik), and were able to expand their economic activities due to the privileges they were given and due to the banishment of many Ragusan merchants who had taken part in the Chiprovtsi Uprising of 1688. Modern Bulgaria A modern nation-state of Bulgaria was formed under the terms of the Treaty of Berlin, which ended the Russo-Turkish War of 1877–78. Under the terms of that treaty, Bulgarian Jews of the new country were granted equal rights. In 1909, the massive and grand new Sofia Synagogue was consecrated in the presence of Tsar Ferdinand I of Bulgaria as well as ministers and other important guests, an important event for Bulgarian Jewry. Jews were drafted into the Bulgarian army and fought in the Serbo-Bulgarian War (1885), in the Balkan Wars (1912–13), and in the First World War. 211 Jewish soldiers of the Bulgarian army were recorded as having died during World War I. The Treaty of Neuilly after World War I emphasized Jews' equality with other Bulgarian citizens. In 1936, the nationalist and anti-semitic organization Ratnik was established. In the years preceding World War II, the population growth rate of the Jewish community lagged behind that of other ethnic groups.