Kirkcudbrightshire, historic county, southwestern Scotland. It lies entirely within Dumfries and Galloway council area. Kirkcudbrightshire forms the eastern portion of the historic province of Galloway. It encompasses the shores of the Solway Firth and Irish Sea between the Rivers Nith and Cree and extends inland across an undulating landscape of hills and valleys, rising in the northwest to the hill of Merrick, with an elevation of 2,765 feet (843 metres).
After the departure of the Romans from Great Britain in the 5th century ad, the Celtic Britons of Kirkcudbrightshire faced invasions by Scots, Angles, Norwegians, and Danes. The Norsemen ruled the region for 300 years after they invaded it about ad 800. Unlike the rest of Scotland, Galloway retained its own code of laws until the late 14th century, a circumstance that vested great power in the region’s feudal barons. In 1245 John de Balliol became overlord of Kirkcudbrightshire through the inheritance of his wife, Devorgilla, daughter of Alan, lord of Galloway. The Balliols, who owned great estates in England and France, brought the best of Norman civilization to the county. Kirkcudbrightshire also became the home of two large Cistercian abbeys, one at Sweetheart (1273–1605) that was endowed by Devorgilla and one at Dundrennan (1142–1605), both of which are now impressive ruins. Kirkcudbrightshire was the site of bitter religious controversy during the Scottish Reformation in the mid-16th century. The royal burgh and former county town of Kirkcudbright, along the estuary of the River Dee, remains the principal town in the area, along with Castle Douglas and Dalbeattie.