Plovdiv reached an agreement that the Principality of Bulgaria and Eastern Rumelia had a common government, Parliament, administration, and army. Today 6 September is celebrated as the Unification Day and the Day of Plovdiv. After the unification, Plovdiv remained the second most populous city in Bulgaria after the capital Sofia. The first railway in the city was built in 1874 connecting it with the Ottoman capital, and in 1888, it was linked with Sofia. In 1892 Plovdiv became host of the First Bulgarian Fair with international participation which was succeeded by the International Fair Plovdiv. After the liberation, the first brewery
Plovdiv Arts; and others. The 2009 International Olympiad in Informatics (IOI) was held at the University of Plovdiv "Paisiy Hilendarski", between 8 and 15 August 2009. The 2009 IOI Honorary Patron was Bulgarian President Georgi Parvanov. Between 1875 and 1906, the Zariphios School was one of the local Greek educational institutions that provided elementary and secondary education. Plovdiv Sports Complex consists of Plovdiv Stadium with several additional football fields, tennis courts, swimming pools, a rowing base with a 2 km-long channel, restaurants, and cafés in a spacious park in the western part of the city just south of the Maritsa river.