This workshop explores historical and contemporary forms of the pledge as a uniquely cross-disciplinary tool and practice of security. From the Greek symbolon to mortgage, warranty, bail, and seal, the pledge calls up an age-old history of securing or crediting an expectation, relation, or undertaking that is curiously absent from the modern disciplinary landscape. The pledge spans legal, financial, and security aspects yet has no prominent place in law, economics, or security studies. Casting a wide net, this workshop aims to take a first step towards a cross-sectional account of the history and politics of the pledge and its continuing relevance today. This comprehensive perspective shall serve to detect the peculiarities of distinct forms of pledge, as well as form a basis to collectively explore how these can inform the theorization of security.