was banned. Vilnius had a vibrant Jewish population: according to the Russian census of 1897, out of the total population of 154,500, Jews constituted 64,000 (approximately 40%). During the early 20th century, the Lithuanian-speaking population of Vilnius constituted only a small minority, with Polish, Yiddish, and Russian speakers comprising the majority of the city's population. On 4–5 December 1905, the Great Seimas of Vilnius was held in the current Lithuanian National Philharmonic Society building with over 2000 participants. It was the first modern national congress in Lithuania. The assembly decided to demand wide political autonomy within the Russian Empire and achieve this by peaceful means. It is considered an important step towards the Act of Independence of Lithuania, adopted on 16 February 1918 by the Council of Lithuania, as the Seimas laid the groundwork for the establishment of an independent Lithuanian state. World War I During World War I, Vilnius and the rest of Lithuania was occupied by the German Army from 1915 until 1918. The Act of Independence of Lithuania, which declared Lithuanian independence without any affiliation to any other nation, was issued in the city on 16 February 1918 with Vilnius as its capital. Regional turmoil 1918–1920 At the end of 1918 Soviet Russia invaded Lithuania with massive forces, and the Lithuanian Army withdrew from Vilnius to the center of the country in order to form a defense line. The German Army withdrew together with the Lithuanian government. The Self-Defence of Lithuania, which was affiliated with the Second Polish Republic, briefly controlled the city and unsuccessfully tried protecting it against the invading Soviet forces. Vilnius changed hands again during the Polish–Soviet War and the Lithuanian Wars of Independence: it was taken by the Polish Army, only to fall to Soviet forces again. Shortly after the Red Army's defeat at the 1920 Battle of Warsaw, in order to delay the Polish advance, the Soviet government ceded the city to Lithuania after the signing the Soviet–Lithuanian Peace Treaty on 12 July 1920. The League of Nations became involved in the subsequent Lithuanian self defense from Poland after it attacked Lithuanian army positions in the south west of Lithuania. The League brokered the ceasefire called the Suwałki Agreement on 7 October 1920. Lithuanians believed that it stopped a Polish aggression. Although neither Vilnius or the surrounding region was explicitly addressed in the agreement, numerous historians have described the agreement as allotting