Plovdiv city was originally a Thracian settlement and subsequently was invaded by Persians, Greeks, Celts, Romans, Goths, Huns, Bulgars, Slavs, Rus people, Crusaders, and Turks. On 4 January 1878, Plovdiv was liberated from Ottoman rule by the Russian army. It remained within the borders of Bulgaria until July of the same year, when it became the capital of the autonomous Ottoman region of Eastern Rumelia. In 1885, Plovdiv and Eastern Rumelia joined Bulgaria. Plovdiv is situated in a fertile region of south-central Bulgaria on the two banks of the Maritsa River. The city has historically developed on seven syenite hills, some
Plovdiv Province capital is the city of Plovdiv; other towns include Karlovo, Sopot, Klisura, Kalofer, Hisarya, Saedinenie, Rakovski, Brezovo, Stamboliyski, Krichim, Perushtitsa, Sadovo, Parvomay, Asenovgrad, Laki, Katunica, Yiagodovo. Plovdiv Province had a population of 715,904 (715,816 also given) according to a 2001 census, of which were male and were female. As of the end of 2009, the population, announced by the Bulgarian National Statistical Institute, numbered 701,684 of which are over 60 years of age. The following table represents the change of the population in the province after World War II: Total population (2011 census): 683 027<br> Ethnic groups (2011 census): Identified