ABSTRACT The UEFA Europa League group stage clash on 24 October and 7 November 2019 between Celtic FC of Glasgow and SS Lazio of Rome offers fascinating insight into ultra social movements as forms of leadership. This exploratory research paper conceptualizes this tie as an Event that provides both a pivotal point of cross-cultural reflection on ultra fan groups as emergent social movements, and a means for the examination of forms of social leadership in contemporary society. In such terms, the paper initiates a critical consideration of The Green Brigade, a self-styled ultra fan group of Celtic FC as an emerging social movement, characterizes the group in terms of the differentiated ultra/ultraS binary, begins to qualitatively address the question as to levels of support for the group among the wider constituency of Celtic supporters, and as such, tentatively explores the groups’ leadership and organizational characteristics. The research concludes that a creative and action-oriented leadership style can be discerned. While organizational characteristics require further examination, intimations of a logic of development emerge.