This paper argues that siblinghood has had an important place in child psychotherapy thinking for many decades. Both psychoanalytic observation of young children and clinical experience have contributed to this. It discusses some reasons for the renewed interest in siblings in the wider psychoanalytic field and emphasises the existential threat to identity posed by the birth of a new baby to the displaced child in the family. The role of siblings as friends as well as rivals is explored and a link is proposed between the development of symbolic thinking and the capacity to give space to siblings in the inner world.