A process of immigration of ethnic non-Bulgarians to Bulgaria began after the country's liberation from Ottoman rule and the restoration of the Bulgarian state in 1878. The first wave of immigrants, mainly from Central and Eastern Europe, brought skills needed in the creation of the new state. Later groups to arrive were Armenian refugees, White Russians, and foreign students. Since the fall of Communism and Bulgaria's entry to the European Union, immigration has increased, with many arriving legally or illegally from less developed countries, and since 2011 the country has been on a migration route used by Syrian refugees.