Buda, Óbuda, and Pest united to form Budapest in Hungary in 1873.
The modern Hungarian capital was created when the western settlements of Buda and Óbuda joined with Pest on the eastern bank of the Danube. The merger took effect on 17 November 1873, establishing a single city whose name combines Buda and Pest. The Danube remains the city’s central geographic feature and a defining part of its history.
Buda developed around the hill and medieval castle on the river’s western side, while Pest grew into a major commercial and administrative center on the flatter eastern plain. Óbuda, meaning “Old Buda,” preserved the area’s older settlement identity and Roman-era connections. The unification followed decades of urban growth and political change after the 1867 Compromise created the dual Austro-Hungarian Monarchy.
A common mix-up is to treat Buda and Pest as interchangeable names for the same historic district. They were separate settlements before 1873, and their contrasting landscapes still shape the city: hilly Buda lies west of the Danube, while flatter Pest lies east. Budapest became the political, economic, and cultural center of Hungary.