Founding in the double sense of the word naturally plays an important role in architecture. But also the history and theory of architecture seem to particularly require the idea of a foundation, a beginning. On the occasion of its 50th anniversary, the Institute for the History and Theory of Architecture (gta) addressed the problem of beginnings – in its own history as well as in architecture in general – and in particular the role of founding myths. As the recurring recourse in architecture to the primitive hut or the three Vitruvian principles of firmness, utility and beauty (firmitas, utilitas, venustas) shows, myths occupy an important place in professional discourse. The contributions to the third issue of the gta papers question the tradition of these myths and examine their potential for the interpretation of the past and for the design of future projects.