The Campbell connection developed through Colin Campbell, first earl of Argyll, and his marriage to Isabel Stewart, John's daughter. The family had acquired the property by 1466. Describing this simply as a purchase in 1465 overlooks the inheritance context and gives the transaction unwarranted precision. In 1489 James IV authorised the name Castle Campbell, making the family's identity explicit in the residence itself.
The tower remained the core of a much larger home. A hall range added around 1500 provided more generous accommodation and space for formal hospitality. Later courtyard buildings further changed the balance between defence and display. A visitor comparing the compact tower with the open court can see how a secure residence became a setting for the social obligations of a powerful family.
Castle Campbell also brought the earls of Argyll within reach of the royal court at Stirling. Mary, Queen of Scots visited in 1563 for a family wedding, a documented episode that belongs to the castle's life as a place of celebration. John Knox had stayed in 1556. The rock traditionally called his pulpit should nevertheless be treated as a traditional association, rather than an independently proven location for a particular sermon.
Late-sixteenth-century alterations included an arcaded gallery, or loggia, facing the courtyard. An inventory of 1595 helps establish that these arrangements already existed by then. Such evidence offers a firmer guide than the temptation to date every decorative feature to a famous royal visit. Gardens and reception spaces were part of a residence designed to impress as well as to shelter its household.
The civil-war history needs a careful distinction. Montrose's supporters devastated Campbell lands in 1645, but HES's detailed assessment says the castle resisted capture. An English garrison occupied it in 1653; Royalists burned it in 1654. Some older summaries confuse these episodes or blame Cromwell's soldiers for the destruction. Charred material found during archaeological work supports a major fire, although it cannot identify every participant by itself.
The family did not restore the castle as its principal Lowland residence. Argyll's Lodging in Stirling offered a different future, while Castle Campbell became increasingly valued as a dramatic ruin. Nineteenth-century landscape improvements also shaped how visitors approached and experienced the glen. Today's picturesque setting therefore combines natural terrain with later choices about paths, views and the presentation of the past.
The property passed to the National Trust for Scotland in 1948 and entered state guardianship in 1950. Conservation includes the tower roof installed in 1956, which should not be mistaken for untouched medieval fabric. The castle is protected as scheduled monument SM13611. Begin with the glen, then compare the tower, hall and courtyard details wherever access allows. The strongest impression is of a residence whose architecture translated family ambition into an unusually memorable landscape.