A review of the literature on “boarding school syndrome” reveals very little about the impact on sibling attachments of children raised in a boarding school. Such children grow up as part of a multigenerational “sibling” and social group with its own rules and cultural norms. After initial confusion children adapt to living amongst strangers; whilst some flourish, many struggle to adapt to living in a group. This article revisits some of the interviews conducted when researching the book Boarding School Syndrome (Schaverien, 2015) with additional and more recent material. In the book there were stories of siblings separated by the stay of one, or both of them, in boarding school. The focus was on children who were sent away and the multiple losses suffered by these children. Here the aim is to focus on the psychological impact of being raised as a member of a large boarding school group, and on sibling relationships, including the immense losses suffered by sibling(s) left at home.