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 Airport and Frankfurt) in 2015 after two years of stable operation. The government have started the first concession procedure back in 2011, but there were no candidates for it. The second attempt for the concession was made in the spring of 2016 when the government have opened a tender for a 35 years concession of the airport, but the tender was shortly cancelled for non-compliance with European rules. In December 2016 the government opened the 3-rd tender for the concession. In the new procedure 3 companies have made the bid for the airport - Silk Road Plovdiv Airport, Consortium Plovdiv Airport