The expansion of higher education in the UK and more widely has resulted in more people attending university, but inequalities remain; for instance, whether a parent has been to university is still a crucial predictor of progression to university. There have been modest increases in the participation of ‘first-generation students’ (the first in the family to attend university). Still, a key theme in the research literature suggests that potential first-generation students and other groups targeted by the widening participation agenda tend to lack the necessary experiences, knowledge, and relationships for successful progression to and through higher education compared to those for whom university participation is common in their family history. Some of the relevant research explores first-generation participation through the Bourdieusian lens. In other words, these studies tend to examine the discontinuities in forms of capital between formal educational contexts and families with no higher education experiences. Such an approach sometimes can veer towards deficit discourses about families with little higher education experience and can be overly deterministic, struggling to explain how some first-generation students are successful in higher education. My research tries to resist such deficit discourses and, perhaps uniquely for UK research, explores the experiences and accounts of first-generation students who have not only succeeded in accessing university and then graduating with undergraduate degrees but have continued to postgraduate study at master's and doctoral level. The thesis seeks to learn directly from these unusual cases about how they explain and account for their educational journeys from childhood onwards. This research examines how first-generation students understand and utilise their capital resources and explores the mechanisms that enable participation and success in this environment. I conducted thirty semi-structured, qualitative, biographical interviews with first-generation postgraduate research students who, by definition, are successful in the higher education context. The interviews were conducted at a post-1992 university in the North of England, and the participant accounts were explored through theoretical thematic analysis – using capital theory - and narrative constructions. The thesis contributes to the field in the following ways: it centres on postgraduate students in a field which overwhelmingly takes undergraduates as the focus; it outlines why ‘first-generation’ status should be defined in a way that includes their siblings, not just parents; it details the meaning and role of ‘support’ in encouraging educational participation and in facilitating the exchange of capital; it illustrates the value of a longer-term perspective on understanding the dynamic nature of successful educational journeys; and it shows that capital is contextual and that ‘critical moments’ can serve as opportunities for individuals to use capital effectively. To my knowledge, this approach has not been explored elsewhere in the literature. The participants in this research revealed that their accumulated social capital enabled successful educational trajectories. From formative parental relations that positioned education as a valuable pursuit to generative ties with peers, teachers, and partners that expanded aspirations and opportunities, these first-generation students leveraged their relationships to propel them into and through higher education. My findings further suggest that tensions can arise when transitioning to postgraduate study as their experiences and parents' expectations can become misaligned. Nevertheless, their accumulated capital enabled them to be committed and agentic in their continued, longer-term educational pursuits (while recognising their new, unique position within the family). I conclude that these relationships, or social capital networks, are crucial for those from families where cultural capital in the form of a degree is not available. Finally, I recommend that educational policies and institutions consider these relationships as facilitative mechanisms when addressing equity issues of access and success in higher education.