The area around the modern town has been inhabited since the Neolithic.
Part of Justinian I's defensive system in the 6th century, the region gained importance as part of the First Bulgarian Empire due to the proximity to the capitals Pliska and Preslav and the passes of Stara Planina.

The first written evidence of the modern town dates from the 17th century, when it was mentioned as the kaza centre Osman Pazarı in Ottoman tax registers.
The settlement was a centre of craftsmanship and trade.

Osman Pazarı was liberated from Ottoman rule on 27 January 1878 by Russian troops under Johann Casimir Ehrnrooth during the Russo-Turkish War of 1877–78.
Most of the Turkish inhabitants of the town left and were replaced by Bulgarians from around Tran and Kyustendil.

Omurtag acquired its present name in 1934, named after the Bulgarian khan Omurtag.
The area around the modern town has been inhabited since the Neolithic. Part of Justinian I's defensive system in the 6th century, the region gained importance as part of the First Bulgarian Empire due to the proximity to the capitals Pliska and Preslav and the passes of Stara Planina.
The first written evidence of the modern town dates from the 17th century, when it was mentioned as the kaza centre Osman Pazarı in Ottoman tax registers. The settlement was a centre of craftsmanship and trade.
Osman Pazarı was liberated from Ottoman rule on 27 January 1878 by Russian troops under Johann Casimir Ehrnrooth during the Russo-Turkish War of 1877–78. Most of the Turkish inhabitants of the town left and were replaced by Bulgarians from around Tran and Kyustendil.
Omurtag acquired its present name in 1934, named after the Bulgarian khan Omurtag.
Omurtag (town)