In 1862 , after Wallachia and Moldavia were united to form the Principality of Romania , Bucharest became the new nation 's capital city . In 1881 , it became the political centre of the newly proclaimed Kingdom of Romania under King Carol I . During the second half of the 19th century , the city 's population increased dramatically , and a new period of urban development began . During this period , gas lighting , horse-drawn trams , and limited electrification were introduced . The Dâmbovița River was also massively channelled in 1883 , thus putting a stop to previously endemic floods like the 1865 flooding of Bucharest . The Fortifications of Bucharest were built . The extravagant architecture and cosmopolitan high culture of this period won Bucharest the nickname of " Little Paris " ( '' Micul Paris '' ) of the east , with Calea Victoriei as its Champs-Élysées
1865 flooding of Bucharest
1865 flooding of Bucharest
Bucharest