The priory was founded in 1230 by Duncan MacDougall, Lord of Argyll -- the same MacDougall dynasty that would later oppose Bruce and lose everything. The monastic order he chose was the Valliscaulians, a contemplative community so obscure that only three of their houses ever existed in Scotland, all founded in the same decade. The site on Loch Etive offered the combination of water access and seclusion that medieval monastic founders valued: the fastest and most reliable transport in thirteenth-century Scotland was by boat, and Loch Etive connected the priory to the sea and to the network of settlements along the Argyll coast. The most widely believed origin of Clan Chattan holds that the MacDougalls appointed Gillichattan Mor as the protector of the priory lands, a connection that wove the monastery into the fabric of Highland clan politics from its founding.

Bruce's 1308 council at Ardchattan came at a pivotal moment in the Wars of Scottish Independence. He had already defeated the MacDougalls at the Battle of the Pass of Brander and was consolidating control over Argyll. Holding a parliament at a MacDougall foundation -- in Gaelic, the language his enemies spoke -- was both a practical necessity and a political statement. From the early fourteenth century, the Prior of Ardchattan held the chantership of Lismore Cathedral, binding the priory to the ecclesiastical power structure of the western Highlands. In 1510, Ardchattan was incorporated as a cell of Beauly Priory and may have become Cistercian, though the evidence is slight. It was annexed to the bishopric of the Isles in 1615, by which time the religious community had long since given way to secular occupation.

The Clan Campbell acquired the priory in the sixteenth century, converting the south range of the monastic buildings into a private dwelling. The choir and transepts of the church served for parish worship until 1731, when a new parish church was erected and the old monastic church fell into disuse except as a burial ground. The fifteenth-century refectory is the only claustral building to survive, though it was subdivided in 1713. The transition from monastery to family home to ruin follows a pattern common across Scotland: religious houses dismantled by the Reformation were absorbed by the clans, adapted to domestic use, and eventually abandoned when newer and more comfortable houses were built nearby.

The monks would have maintained a garden for practical purposes, but the fine site -- with views across Loch Etive to Ben Cruachan and the hills of Mull -- was recognized and developed when the Campbell house was built in the early seventeenth century. Some of the oldest trees on the estate date to that period. Most of the present garden was created in the nineteenth and twentieth centuries, and a walled kitchen garden continues to produce. The priory's gardens represent an unbroken tradition of cultivation stretching back nearly eight centuries, a continuity that the monastery itself could not sustain. Today the ruins and gardens are open to visitors, the yew trees still standing -- whether or not Bruce ever inspected them -- and Loch Etive still carrying boats past the shore where monks once chanted in Latin and a king once spoke in Gaelic.