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 the Slavic name began to appear as "Papaldiv/n Plo(v)div, Pladiv, Pladin, Plapdiv, Plovdin", which evolved from a Thracian variant "Pulpudeva". As a result, the name has lost any meaning. In British English the Bulgarian variant "Plòvdiv" has become prevalent after World War I. The Crusaders mentioned the city as "Prineople", "Sinople" and "Phinepople". The Ottomans called the city "Filibe", a corruption of "Philip", in a document from 1448. Plovdiv is located on the banks of the Maritsa river, southeast of the Bulgarian capital Sofia. The city is in the southern part of the "Plain of Plovdiv", an alluvial plain that