The present dissertation investigates pupil fraternities in the Swedish state grammar school system from 1850 to 1914, in an effort to contribute to the understanding of peer group socialisation as part of the overall pedagogical process. Focus is trained on the practice of liberal education (Sw. bildning ) and the construction of collective identity. Modern pupil associations emerged in the mid-nineteenth century from the ruins of outdated educational traditions. Due to sharpened discipline, institutional changes and external societal pressure, previously existing corporative modes of organisation successively disappeared. To fill the void, pupils began founding fraternities, thereby introducing a new organisational form and a new set of activities based on an ideological foundation more in sync with the ideals of the emerging industrial society. Infused with the liberal, neo-Romantic ideals of the day, the introduction of fraternal life laid out new tools for selfadministered socialisation. After analysing the growth of pupil associations in the mid- nineteenth century, the thesis concentrates on fraternal practice at one particular institution, Umeå State Grammar School. This case study shows that fraternal activity revolved around creating lending libraries and reading circles, assemblies, school magazines and aesthetic pursuits including musicmaking, singing, acting and dancing. The thesis suggests that the fraternity had a structuring impact on the student body as a whole, serving to homogenise the school experience and provide a viable alternative to the allurements of town life. Subjects favoured by the fraternity included philosophy and ethics, literature and history and, to a lesser extent, current events. A slight shift in interest toward the natural sciences can be detected at the end of the period under investigation. Furthermore, it is revealed that peer socialisation encouraged identification with the school. It transmitted a set of values stressing idealism and anti-materialism, patriotism and regionalism, intellectualism (as opposed to athleticism), religious and/or secular piety, historism, cultural and political traditionalism, an acknowledgement of the powers – and limitations – of youth and an idealisation of friendship and camraderie. Insofar as social mores and relationships between the sexes was concerned, peer socialisation also provided pupils with practical instruction on proper conduct, and laid the foundation for an ambiguous understanding of the opposite sex. It promoted an ideal of masculinity closely associated with what may be characterised as the civil servant ideal. The thesis finally reveals that strong links were forged between fraternities on a regional, nationwide and Nordic level, bearing strong resemblance to contemporary social youth movements regarding attitudes toward society, culture and knowledge. Upper secondary school fraternities considered themselves guardians of the nation and its culture and became a conformist force in late nineteenth-century Sweden. On the other hand, pupils also constituted an active force in the modernisation of Swedish institutional practice, in the vitalisation of the state grammar schools, and as forerunners in the conceptualisation of a new cult of youth.