Kilchurn Castle was founded in the mid-fifteenth century by Sir Colin Campbell, first lord of Glenorchy, on a small island or low peninsula at the head of Loch Awe. The original stronghold centered on a five-story tower house protected by a courtyard wall. Water separated it from much of the surrounding land, giving the Campbells a defensible residence beside routes through the western Highlands. From Kilchurn they managed expanding estates, cultivated alliances, and established a branch of the Campbell kindred that later became earls of Breadalbane.

Successive generations enlarged the castle as the family's wealth and political reach increased. Additional ranges, corner towers, kitchens, chambers, and service buildings turned the compact tower into a more complex household. Kilchurn was both a residence and a statement of lordship in a region where control depended on tenants, kin, livestock, and access through glens and waterways. The Campbells spent less time there as they acquired other houses, but the ancestral castle retained symbolic and strategic value during the religious and political conflicts of the seventeenth century.

Around 1690 Sir John Campbell, later first earl of Breadalbane, converted Kilchurn into a barracks capable of housing a substantial garrison. A purpose-built block and altered defenses reflected the government's effort to control the Highlands after the Revolution of 1688. Troops used the site during the Jacobite risings, when loyalty to the Hanoverian state and support for the exiled Stuarts divided communities and noble families. The change from private residence to barracks also showed how older tower houses could be adapted for more centralized military authority.

The castle's usefulness declined as roads, artillery, and new government forts reshaped Highland security. The Campbells had shifted their principal residence elsewhere, and Kilchurn was abandoned during the eighteenth century. A lightning strike and fire, traditionally dated to the 1760s, contributed to the loss of roofs and interiors. Changes in Loch Awe's water level later joined the former island more firmly to the shore. Artists and travelers increasingly valued the empty ruin for its dramatic setting, making it part of the romantic image of the Highlands.

Kilchurn entered state care in the twentieth century, and conservation has focused on stabilizing masonry exposed to water, frost, wind, and periodic flooding. The roofless buildings still reveal the transition from compact medieval tower house to courtyard residence and government barracks. Archaeology and architectural study continue to refine the dates of individual phases. The castle's history connects the rise of a powerful Campbell family with the later imposition of state military control, followed by abandonment and picturesque rediscovery. Its celebrated landscape is therefore also evidence of changing transport, politics, and land use.