After the devastation of World War I, in the framework of a humanitarian relief project, thousands of Hungarian children were transported to Belgium for a couple of months holiday. They travelled without their parents and stayed with Belgian host families. From the moment of their arrival to their host families, the Hungarian parents together with the Belgian hosts assisted the children to start up a written relationship between the two families. As the Hungarian parents were most anxious to watch over their children in spite of the distance that separated them, correspondences served parental purposes. Exchanging letters was probably the only possible, hence most significant communication channel for thousands of families to maintain their unity through time and space. The letters did more than just serving unity; they provided these families and their far-away children with a sense of continuity and bonding. They also facilitated the changing of family dynamics. Based on the content and textual analysis of personal correspondences of five Hungarian children and their families, this study examines the various ways correspondence sustained and developed family relationships – particularly parent-child relations – which were rendered vulnerable by separation. It explores how Hungarian families and Belgian families, in a joint enterprise, negotiated time, space and identity in their letters.