Eisenstadt is the capital city of the Austrian state of Burgenland. With a population of 15,074, it is the smallest state capital and the 38th-largest city in Austria overall. It lies at the foot of the Leitha Mountains hill range. From 1648 to 1921, Kismarton/Eisenstadt was part of the Habsburg Empire's Kingdom of Hungary and the seat of the Hungarian noble family Eszterházy.