This police force was formed on 16 May 1975 as a merger of the pre-existing Northern Constabulary, the Ross and Sutherland Constabulary (itself a merger of Ross and Cromarty Constabulary and Sutherland Constabulary) and the Inverness Constabulary (a merger of Inverness Burgh Police and Inverness-shire Constabulary), along with the northernmost portion of the Argyll County Police area, and the Nairn part of the Scottish North East Counties Constabulary. The previous Northern Constabulary had been created in 1969 by the merger of the Caithness Constabulary, Orkney Constabulary and Zetland Constabulary.