Recent developments in applications of network analysis to history are leading to a new way of thinking about how social and economic actors interacted in the past. Focus on the social tie has resulted in increased interest in relational instruments that have not previously been taken into great consideration. This article analyses some of these instruments, and particularly godparenthood and marriage witnessing, as ways to establish formal and public ties. It shows that formalisation, ritualisation and publicity of ties were used by entrepreneurs to establish trust with their business associates, in situations when information was asymmetric or when institutions were perceived as inefficient in guaranteeing mutual good behaviour. The paper underlines both factors of continuity and factors of change over time, from the Middle Ages to today, paying particular attention to the consequences of Reformation and Counter-Reformation on one hand, and of Industrial Revolution and Modernization on the other. It shows, in the light of the most recent literature, that much of what we think to know about the declining importance, for social and economic activity, of family ties and of weaker ties such as godparenthood, is actually a kind of prejudice originating from a twentieth-century ideology of the market in which ancient practices struggle to find a place but are not abandoned.