This thesis explored the experiences of children and their families as the children started school at one Aotearoa/New Zealand primary school. The study followed the progress of seven case study children and their families, from the children's last months in early childhood education, when they were four-years-old, until the children were eight, and had been at school for three years. Their stories are nested within a broader framework, looking at the transition experiences of 16 other children and families. Using an interpretive methodology, interview and observation data were gathered from the children, their parents, their early childhood and new entrant teachers, and other relevant school personnel. This provided a 'rich description' of the year in which the children's transitions took place. A series of interviews over the four-year period captured the case study participants' ongoing experiences and reflections. An ecological framework was used to analyse the ways in which the children learned to 'do school' and took on the role of school pupils. It revealed the complex interweaving of characteristics of individual children, and their immediate and more remote environments, that led to different patterns of experiences. This helped to uncover why some children apparently settled happily into school, and for others the experience seemed more challenging. In understanding the children's experiences, it was important to look at the influences over time, rather than a single characteristic of either the child or context. It appeared that most difficulties were short-lived, but some children had ongoing problems that were potentially detrimental to their progress. The study provides insights into why this happened, and indicates possible actions to address the difficulties. In the interrelated experiences of children, parents and teachers, the beliefs and practices of the adult participants helped to shape what happened for children. Complexity was evident here too, with transition practices that suited one group of participants sometimes viewed as problematic by others. There were also many, (sometimes contradictory), ideas, that appeared to be underpinned by different views about development. For example, an important issue for the school was the children's development of independence. This was at odds with the more sociocultural and ecological positions evident in the parents' and some early childhood teachers' beliefs about how children could be supported. The focus on independent children carried through into assessment practices at school, which tended to measure isolated skills, and overlooked the influence of the teacher-created environment on children's learning and behaviour. Different views about learning led to differing ideas about how children should be prepared for school. These beliefs were also played out at the macro level in systemic differences between early childhood education and school. Hence, the children's journey to becoming a school pupil involved crossing a cultural, as well as a physical border. The differences between the 'cultures' of home and early childhood center on one side, and school on the other, have been well documented in previous research. This study provides new insights into how these could be negotiated. Instead of eliminating differences to provide a smooth or seamless transition, I argue for sociocultural approaches, which capitalise on the developmental possibilities of coping with change. This involves supporting children in the process of becoming a pupil, where the difficulties appear to be beyond those that they can negotiate alone. Overall, it is proposed that enabling children and their families to become 'border crossers' into school requires those supporting them to recognize the multiple, interwoven influences on the process, to know what the hazards are from the border crossers' point of view, and have sufficient understanding of different perspectives to communicate in ways that are 'intelligible' to those involved.