The history of modern Budapest is a tale of the unification of three cities, yet its roots reach deep into the centuries, to the times of the Roman Empire and even earlier. The journey from ancient settlements to one of Europe's most beautiful capitals was long and eventful.
Foundation and first mentions. Long before the arrival of the Hungarians, a Celtic settlement known as Ak-Ink existed in this territory. In the 1st century AD, the Romans founded the city of Aquincum here, which soon became the capital of the province of Pannonia. The Romans built roads, amphitheatres, and baths, utilising the local thermal springs. After the departure of the Romans and several centuries of change, Hungarian tribes arrived in these lands around the year 895. However, officially, the city we know today was born much later. On November 17, 1873, the historic unification of three neighbouring cities on the Danube occurred — Buda, Pest, and Óbuda (Old Buda), resulting in the emergence of Budapest.
Key factors in the formation of the city were closely linked to its geography and political role. The mighty Danube both divided and connected the future parts of the capital. The hilly terrain of Buda was ideal for constructing defensive structures, such as the royal castle erected after the Mongol invasion in the 13th century. Meanwhile, the flat plains of Pest became a natural hub for trade and crafts. Politically, Buda was proclaimed the capital of the Kingdom of Hungary in 1361, becoming its political heart. Pest, on the other hand, flourished as an economic centre. The decisive impetus for unification and rapid growth was the city's transformation into one of the two capitals of the Austro-Hungarian Empire in 1867.
Early cultural and economic features became apparent long before the unification. Even in the Roman era, Aquincum was a developed city with a population of up to 40,000 people, central heating in homes, and a vibrant public life. In the Middle Ages, after Buda became the royal residence, the city turned into one of Europe's significant centres. The 19th century became the city's "Golden Age". The construction of the Széchenyi Chain Bridge, the first permanent bridge across the Danube (1849), physically connected Buda and Pest, becoming a symbol of future unity. After the unification, Budapest experienced rapid growth: industrial enterprises, banks, and the first metro line in continental Europe appeared, cementing its status as a major European capital.