The Slovenian city of Ljubljana is the largest city in the country with around 280,000 inhabitants and is also the capital of the Balkan state.

The first lake dwellings on pile dwellings existed in the Ljubljana Marshes as early as 3,500 BC. The first Illyrian and Venetian settlements existed from 1,000 BC, before the first Celtic period began around 400 BC. The Romans built the first military fortifications in the first century BC before founding the settlement of Emona in 14 AD. After the fall of the Roman Empire, this settlement disintegrated and the Slavs settled in the region before the area fell under the rule of the Franks around 800.

The first documentary mention of a settlement in Ljubljana dates back to 1144, and it was first referred to as a town in 1220. Market rights and a town wall were first documented in 1243. After several disputes, Ljubljana became the property of the Habsburgs in 1278 and became the capital of the Duchy of Carniola in the Holy Roman Empire. A Turkish invasion was averted in 1415. In 1461, the town became a bishop's see; several schools were built to accommodate the steadily growing population. In 1754, the town had 9,300 inhabitants. In 1797, the first daily newspaper of today's Slovenia was published. In the turbulent 19th century, rule changed frequently between the Napoleonic and Austro-Hungarian monarchies.

After the First World War, Slovenia was briefly part of the Kingdom of Serbs, Croats and Slovenes. The University of Ljubljana was founded during this period. After several changes of jurisdiction before and during the Second World War, Slovenia became part of the Federal People's Republic of Yugoslavia in 1945. Only after the collapse of the Eastern Bloc did the state with its capital Ljubljana become independent in 1991.

On March 30, 1977, a town twinning agreement was signed between Ljubljana and Wiesbaden in Slovenia. During a return visit on September 21 of the same year, a delegation from Ljubljana signed the Golden Book of the Hessian state capital.