Fosterage was a Celtic practice where children were sent from their natal family to be raised in another household. This differed from other early modern European alloparenting practices (such as wet-nursing, service, and apprenticeship arrangements) as ‘fosterage was a socio-political arrangement often used by chiefs to ensure continuation of close relations with the head of a cadet branch, a neighbouring clan or one of his own fine’. The resulting fictive kinship was intended to develop bonds of loyalty and friendship between families that benefited all of their members. One such bond began in March 1633, when arrangements for the fosterage of the four-year-old Archibald Campbell were negotiated. Archibald was the son of Archibald Campbell, lord of Lorne, who later became 8th earl of Argyll and 1st marquis of Argyll. The foster-father was a member of Lorne's fine (the principal men of the clan), a relation by the name of Colin Campbell, laird of Glenorchy. The Glenorchy Campbells were descended from the house of Argyll and therefore were part of Clan Campbell, yet they formed a distinct lineage, which Colin Campbell was careful to assert in his commissioning of George Jameson's unique portrait, ‘The Campbell of Glenorchy Family Tree’.

Ideologically, fosterage was about creating bonds of fictive kinship between families in clan society. These bonds had far-reaching political, economic, military and social implications for that society. Very little research exists on Scottish fosterage; the role that women and children played in the fosterage contract has been particularly neglected. Yet most of the actual experience of fosterage occurred far from the meetings of powerful clansmen, existing instead within the realm of women and the household. As women were almost solely responsible for the care and education of young children, especially those under seven years of age, the success of the fosterage relationship depended to a significant degree on the actions of women. As Jane Dawson argued in her work on Clan Campbell, ‘the political importance of a wife to her husband has been underestimated’. Equally, it was real children who were removed from their homes; they were the glue that was to bond the two families together, thus their willingness and ability to connect with their foster family was significant to how successfully the families bonded.