This article examines the role of the Corston Independent Funders’ Coalition (CIFC), a group of grant-making trusts and foundations that came together in 2008 to take a direct and active advocacy role. Using an existing policy reform blueprint, CIFC aimed to influence government policy on the treatment of women in the United Kingdom’s criminal justice system. Conceptualizing the CIFC as an ad hoc advocacy network, the authors use a retrospective mixed-methods approach to explore the context that gave rise to the CIFC, examine the setting-up and operation of the network, and reflect on its achievements. The case highlights some of the tensions associated with advocacy networks and points toward the challenges of defining and building identity in a preoccupied policy space. It raises questions about whether and how established foundations might be able to take on a more direct policy advocacy role.