Proof on Paper? Undocumented Loans and the Use of Written Collateral in Jewish-Christian Credit Transactions in Fourteenth-Century German Towns

Abstract Medieval credit transactions operated in a landscape of uncertainty, where the presence or absence of written documentation did not guarantee financial security. While written debt instruments provided a formal record of obligations, lenders and borrowers navigated risk not only through documents but also through oral agreements, court acknowledgments, and physical collateral. This article examines the conditions under which creditors in fourteenth-century German towns opted for written documentation over alternative forms of collateral and the underlying factors influencing this choice. Rather than serving as static proof, written debt instruments could be undermined by shifting obligations, partial repayments, or contested claims. By tracing how creditors wielded physical documents in court and used them as instruments of negotiation, this article highlights the dual function of written collateral as both legal proof and material leverage, revealing how individual moneylenders navigated credit relationships and made strategic choices to manage risk within the shifting dynamics of medieval urban economies.