Is the capital and the largest city of Hungary, and one of the largest citiesin the European Union. It is the country's principal political, cultural, commercial, industrial, and transportationcentre,sometimes described as the primate cityof Hungary. According to the census, in 2011 Budapest had 1.74 million inhabitantsdown from its 1989 peak of 2.1 milliondue to suburbanisation.The Budapest Metropolitan Areais home to 3.3 million people.The city covers an area of 525 square kilometres (203 sq mi).Budapest became a single city occupying both banks of the river Danubewith the unification of Budaand Obudaon the west bank, with Peston the east bank on 17 November 1873.

The history of Budapest began with Aquincum, originally a Celticsettlementthat became the Romancapital of Lower Pannonia Hungarians arrived in theterritoryin the 9th century. Their first settlement was pillaged by the Mongols in 1241–42.The re-established town became one of the centres of Renaissance humanist cultureby the 15th century.Following the Battle of Mohács and nearly 150 years of Ottoman rule,the region entered a new age of prosperity in the 18th and 19th centuries, and Budapest became a global city after its unification in 1873.It also became the second capital of the Austro-Hungarian Empire, a great power that dissolved in 1918, following World War I. Budapest was the focal point of the Hungarian Revolution of  1848, the Hungarian Republic of Councils in 1919, the Battle of Budapest in 1945, and the Revolution of 1956.