Eisenstadt (German pronunciation: [ˈaɪzn̩ʃtat] ⓘ; Austro-Bavarian: Eisnstod; Hungarian: Kismarton; Croatian: Željezni grad or Željezno; Slovene: Železno) is the capital city of the Austrian state of Burgenland.

During this time, the composer Joseph Haydn lived and worked in Eisenstadt as a court musician under the patronage of the Esterházy family.

As the state capital of Burgenland, it functions as a center of public administration and services[5][6] and is the seat of three institutes of higher education.

Eisenstadt lies on a plain leading down to the river Wulka, at the southern foot of the Leitha Mountains, about 12 kilometres (7 miles) from the Hungarian border.

The city previously included the districts (Ortsteile) of Eisenstadt-Stadt, Eisenstadt-Oberberg, Eisenstadt-Unterberg, and Eisenstadt-Schloßgrund (Kismartonváralja).

The first written mention of the town is from 1264 as "minor Mortin", matching the Hungarian name, Kismarton, which recalls Martin of Tours, the patron saint of the main church.

The fortress built on the original earth works was destroyed by the troops of Margrave Leopold III of Austria.

These Hungarian princes permanently changed the face of the city due to their extensive construction, especially on their castle, Schloss Esterházy.

The appointment of Joseph Haydn as the prince's Hofkapellmeister (court orchestra director, composing and performing music) began the great artistic period in the city's history.