The human occupation of the Bulgarian territory dates back to very ancient times and recent palethnological findings have identified a very evolved Neolithic, which seems to predate that of the Near East. After the Roman era, the country was for a long time a land of transits and only with the settlement of the Bulgarians was there a political organization that definitively fixed the fundamental lines of territorial occupation. The Ottoman domination not only spread Islamic religion and customs (even a small part of the Slavic population remained Islamized: the Pomaks, in the region of the Rhodope Mountains) but also introduced large quantities of Turkish population; despite this, the ethnic group is quite compact because, following agreements with Turkey, in 1951 they returned to the country of origin some hundreds of thousands of people who lived mainly in eastern Bulgaria. At the 2001 census, Bulgarians made up the majority of the population (83.9%); the minorities, significantly reduced following the mass exodus that took place after the Second World War, are represented by large groups of Turks (9.4%) and Gypsies (4.7%) and by small minorities of Macedonians, Romanians, Armenians (2%).
According to iamhigher, the distribution of the population is quite irregular, and this largely due to the morphological differences of the country: the maximum values are recorded in the Marica valley (the district of significantly reduced following the mass exodus that took place after the Second World War, they are represented by large groups of Turks (9.4%) and Gypsies (4.7%) and by small minorities of Macedonians, Romanians, Armenians (2%). The distribution of the population is quite irregular, and this largely due to the morphological differences of the country: the maximum values are recorded in the Marica valley (the district of significantly reduced following the mass exodus that took place after the Second World War, they are represented by large groups of Turks (9.4%) and Gypsies (4.7%) and by small minorities of Macedonians, Romanians, Armenians (2%). The distribution of the population is quite irregular, and this largely due to the morphological differences of the country: the maximum values are recorded in the Marica valley (the district of Plovdiv, the most populated, has 117 residents / km²) and in the foothills that slopes down to the Danube. An exceptionally populated area is represented, within the mountainous areas, by the Sofia basin; relative density high are also found on the coast. However, compared to European values, Bulgaria is overall sparsely populated. This is the result of several factors, including the long Ottoman rule, which with its serious conditions of hardship and poverty has contributed to slowing down demographic development. A significant increase occurred after the liberation from the Turks, particularly in the first decades of the century. XX: in 1900 there were fewer than 4 million people, increased by over a million in the first twenty years. Subsequent demographic developments have seen the trend of most European countries, with a tendency to settle on gradually lower values; and therefore, from the end of the Eighties onwards, with a progressive decrease. In 2007 the estimates indicated a strongly negative population growth rate (-0.5 per thousand), with a clear prevalence of deaths (15 per thousand, which reaches 8.8 per thousand as regards infant mortality) on births (10 per thousand), by virtue of a rather modest fertility rate (1.4), to which was added an equally net negative migratory balance (-4.3 per thousand). Until the Second World War Bulgaria remained a country with a characteristic rural structure, affected to a very modest extent by the urbanization process: the urban population, which at the 1887 census represented 19% of the total, in 1944 was still just 24 %. The profound changes induced by the communist regime with agrarian collectivization and industrialization led to a rapid development of urbanization (so much so that in 2009 the urban population reached 71.2%). The reason for this phenomenon is not only to be found in rural immigration, but also in the urban promotion of small towns and villages and in the creation of some new cities that took place in the Communist forty years. The process, however, was not homogeneous and while it affected some cities, the demographic consistency of others remained unchanged.
The capital has grown rapidly and nine cities have passed the 100,000 mark. Sofia, the only metropolis in Bulgaria, emerges in this urban network: in an eccentric position with respect to the borders of the state, it is instead excellently located at the intersection of the natural roads that unite Belgrade to Istanbul and Budapest to Thessaloniki. It has become a populous capital, with an important role also in the economic field: it exceeds one million residents. and it greatly surpasses it if we consider the surrounding centers which with it make up the Great Sofia. The latter tends to join the West with the Pernik agglomeration, a well-known coal, steel and energy center only about thirty kilometers away. The second Bulgarian city, Plovdiv, “capital” of the Marica valley, is an industrial and commercial center on an important road and railway artery, located in a rich agricultural area and enhanced by an international fair; in the same valley is Dimitrovgrad, undergoing considerable expansion thanks to the enhancement of important lignite deposits, such as Stara Zagora. On the Black Sea the cities have port functions: the main ones are Varna, on the northern route of the country, of which it is the third city, and Burgas, on the southern one; active port on the Danube is Ruse, which is one of the major centers, with Pleven, of the Danube area.