The administrative centre of the municipality was the village of Halse, which at that time was a suburb of the town of Mandal.

The municipality of Halse og Harkmark encompassed the rural areas that surrounded the town of Mandal, including many islands such as Hille, Skjernøy, and Pysen (Norway's southernmost point).

On 1 July 1921, a part of Halse og Harkmark (population: 221) was transferred to the town of Mandal.

On 3 November 1917, a royal resolution changed the spelling of the name of the municipality to Halse og Harkmark.

The first element is hals which means "neck", referring to the piece of land between the Skogsfjorden and the river Mandalselva.

[7] The municipal council (Herredsstyre) of Halse og Harkmark was made up of representatives that were elected to four year terms.