Although it has been a ruin for at least three hundred years, Dunure Castle was once the main fortress of the powerful Kennedy family, the Earls of Cassilis. Today the Kennedys are much more closely associated with Culzean Castle, less than four miles down the coast, but for several centuries from the 1200s, Dunure Castle was by far the more important of the two.
The castle's origins probably date back to at least the 1200s when a stone keep was built on an easily defensible rocky outcrop overlooking the Firth of Clyde. The Kennedy family prospered, with one member marrying a daughter of King Robert III while another went on to become Bishop of St Andrews and the founder of St Salvator's College.
As the family prospered, so their castle expanded. New ranges of buildings were added at a lower level slightly inland, and a curtain wall was erected to surround the whole castle. The new buildings included a kitchen range and a chapel, a great hall and a prison, plus living accommodation for the family and their retainers.
Dunure Castle featured as a footnote in history on a number of occasions during its active life. In 1429 a meeting took place here - presumably because it was seen to be neutral territory - between James Campbell, representing King James I of Scotland and John Mor MacDonald, representing the Lord of the Isles. Violence broke out and MacDonald was killed. James I's efforts to contain the outrage of the Lords of the Isles by executing Campbell did not prevent a subsequent uprising by them.
For three days from 4 August 1563, Mary Queen of Scots stayed at Dunure Castle as the guest of Gilbert Kennedy, the 4th Earl of Cassilis. Mary made a number of progressions around her realm during her short reign, and Dunure thus joins a long list of those who would be able to display a "Mary slept here" plaque.
Gilbert Kennedy was not always so hospitable towards his guests. The arrival of the Reformation in Scotland in 1560 led to a huge land-grab, in which secular landowners and lairds tried hard to take control of lands and properties previously held by abbeys across Scotland. Gilbert, 4th Earl of Cassilis, managed to gain control of at least some of the lands of Glenluce Abbey in Galloway, allegedly by paying a monk to forge the necessary signatures on a charter under which abbey lands were passed to him. Gilbert then, also allegedly, had the monk killed by a paid assassin, who in turn he hung on a trumped up charge of theft.
Gilbert Kennedy's efforts to gain control of the lands of nearby Crossraguel Abbey were equally unscrupulous, but caused him more problems. The last Abbot of Crossraguel, who died in 1564, was Quintin Kennedy, Gilbert Kennedy's uncle. He was replaced by a lay commendator (or administrator) called Alan Stewart, who spent much of the next five years fending off assorted attempts by Gilbert, 4th Earl of Cassilis, to take ownership of the abbey lands. Matters came to a head on 29 August 1569 when, according to a complaint later made to the Scottish Privy Council by Alan Stewart, Gilbert had Stewart kidnapped, taken to Dunure Castle, and roasted over an open fire in the castle kitchens until he agreed to sign over the abbey estates to Gilbert. This he apparently did after two turns on the spit.
The story then gets rather confused. A distant relative of Gilbert's, Thomas Kennedy of Bargany (who wanted the abbey lands for himself), stormed Dunure Castle and released Alan Stewart. But before Thomas Kennedy could escape he was in turn besieged in the castle keep by a larger force which had arrived under the personal command of Gilbert Kennedy. The ensuing fight between forces occupying different parts of the castle caused considerable damage to its structure. How all this was resolved is a little unclear: but it seems that Gilbert Kennedy was eventually instructed by the Scottish Privy Council to pay Alan Stewart a pension for life in compensation for his treatment: but it also seems that Gilbert may have been allowed to retain the abbey lands signed over to him under duress by Stewart.
By the mid 1700s, Dunure Castle was already a ruin, and it then spent more than a century being used as a quarry for every building project in the area. But by the mid 1800s its potential as a romantic visitor attraction was being appreciated, and this brought a halt to the systematic destruction of what was left. After many years as a derelict and dangerous ruin, the castle has recently been consolidated and is now partly accessible to visitors.