A relatively larger number of ethnic Russian workers settled in Tallinn and Narva during the period of rapid industrial development at the end of the 19th century and the beginning of the 20th century. After the First World War, the share of ethnic Russians in the population of independent Estonia was 7.3%. About half of these were indigenous Russians living in Narva, Ivangorod, the Estonian Ingria and the Petseri County, which were added to Estonia territory according to the 1920 Peace Treaty of Tartu, but were transferred (without Narva) to the Russian SFSR in 1944.