The title was created in 1699 for the Agnew family, who held the hereditary sheriffship of Galloway for many generations.

The Barony of Lochnaw was created in 1699 during the reign of King William III of England and Scotland.

The title was granted to Sir Andrew Agnew, a prominent landowner in the region and a key figure in the Agnew family, who also held the title of hereditary sheriffs of Galloway.

His family has been heavily involved in cultural and historical preservation, notably through the Baron Courts of Prestoungrange, Dolphinstoun, and Lochnaw.

[6] Today, the Baron of Lochnaw, alongside the Baron Courts of Prestoungrange and Dolphinstoun, supports various cultural and historical projects across Scotland, focusing on the preservation of the baronial legacy and community development.