A Thracian settlement was founded at the place of the modern town in the 5th-4th centuries BC and the Romans developed it into an important stronghold, balneological resort and trade junction called Pautalia in the 1st century AD. Many Thracian and Roman objects are exhibited in the city's Regional History Museum, most notably an impressive numismatic collection.
The Hisarlaka fortress was built in the 4th century and the town was mentioned under the Slavic name of Velbazhd (???????, meaning "camel") in a 1019 charter by the Byzantine Emperor Basil II. It became a major religious and administrative centre.
During the reign of Kaloyan of Bulgaria, the town became part of the Second Bulgarian Empire, acquiring its modern name in the 16th century, named after local feudal lord Konstantin Dragash (ruled from 1379 to 1395). In 1330 the Battle of Velbazhd took place in the vicinity of the town. After that war, the city came under Serbian rule, which lasted between 1330-1355. About 1355 Velbazhd and its region were included in the semi-independent feudal Velbazhd principality of Despot Deyan. In 1372 the Turks conquered the town. It was known as K�stendil under Ottoman rule. The name K�stendil was derived from Constantine Dragas' name. The city was a sanjak centre initially in Rumelia province, after that in the Bitola and Ni� vilayets. It was a kaza centre in the Sofia sanjak of Danube Province until the creation of the Principality of Bulgaria in 1878.
The residents of Kyustendil took an active part in the Bulgarian National Revival and crafts and trade flourished. The town was liberated from Ottoman rule on 29 January 1878
