The County of Kincardine, also known as Kincardineshire or The Mearns (from A' Mhaoirne meaning 'The Stewartry') was a local government county on the coast of northeast Scotland. It was bounded by Aberdeenshire on the north and west, and by Angus on the south.
The county town was originally the town of Kincardine (not, as many believe, the village of Kincardine O'Neil, which was in the County of Aberdeen). The town of Kincardine, however, ceased to exist during the Middle Ages. The only visible sign of its previous existence is the ruin of Kincardine Castle, 2 miles north-east of Fettercairn . In 1296, King John Balliol wrote a letter of surrender from the castle to Edward I of England after a short war which marked the beginning of the wars of Scottish independence. In 1600 Parliament caused the government of Kincardineshire to be conducted at the Stonehaven Tolbooth. The county used to go as far north as the River Dee but in 1891 the Royal Burgh of Torry was incorporated into Aberdeen.
The county was abolished in 1975, and was subsumed into the Kincardine and Deeside district of the Grampian region. When the Grampian region was divided into unitary council areas in 1996, the district was absorbed into the Aberdeenshire council area.
There was a Kincardineshire constituency of the House of Commons of the Parliament of Great Britain from 1708 to 1801 and of the Parliament of the United Kingdom from 1801 to 1918, representing the county of Kincadineshire, minus the parliamentary burgh of Inverbervie. Inverbervie was a component of the Aberdeen District of Burghs from 1708 to 1832 and of the Montrose District of Burghs from 1832 to 1950.
In 1950 Kincardine and Western Aberdeenshire was divided between the West Aberdeenshire constituency and the North Angus and Mearns constituency. North Angus and Mearns then covered the whole of the county of Kincardineshire, including the former parliamentary burgh of Inverbervie, and part of the county of Angus, the latter being previously within the Forfarshire constituency.
In 1983, eight years after the abolition of the local government county of Kincardineshire, North Angus and Mearns was replaced by new constituencies.
The ancient Causey Mounth road was built on high ground to make passable this only available medieval route from coastal points south to Aberdeen. This ancient passage specifically connected the Bridge of Dee to Muchalls Castle, Cowie Castle (and effectively Dunnottar Castle). The route was that taken by the Earl Marischal and Marquess of Montrose when they led a Covenanter army of 9000 men in the first battle of the Civil War in 1639.