[1] Following the Berlin Congress, the Russian Empire was forced to withdraw its troops from Bulgaria but left a large number of specialists and functionaries who assisted the formation of the Bulgarian army and state institutions.
Among the temporary or permanent settlers were ethnic Jews, Germans and Austrians, Hungarians, Serbs and Montenegrins (settled in a few villages in northeastern Bulgaria), Croats, Slovenes, Poles, Ukrainians and Rusyns, and others.
The first larger compact group of non-Bulgarian immigrants in contemporary Bulgarian history to settle in the country were the Armenian refugees fleeing the persecutions in the Ottoman Empire.
A smaller wave of new immigrants arrived in Bulgaria during the socialist regime (1944–1989), when large numbers of foreign students came to study in Bulgarian universities and many of them remained.
The country's accession to the EU on January 1, 2007 has not yet led to a significant rise in immigrants, although there is a growth in the number of refugees from Afghanistan, Iraq, Sub-Saharan Africa, Armenia and some Christian Palestinians.
The recent decade saw a growth of private businesses opened by citizens of Russia, Ukraine, Turkey, China, Bosnia and Herzegovina and the countries in the Middle East, notably Syria and Lebanon.
According to official data, the number of permanent foreign residents in Bulgaria as of December 2008 is 66,806[3] and the vast majority of these come from Russia (21,309), Ukraine (5,350), the Republic of North Macedonia (4,375), Turkey (3,828) and Moldova (2,203).