Chapter 5 analyzes the broad participatory access, robust engagement, and critical impact of NGOs at the International Criminal Court (ICC). It illustrates that these strong relationships and channels of access were facilitated by pre-established relationships and legitimacy born from the prior advocacy work of NGOs coupled with the fledging Court’s need for greater resources and state cooperation. NGOs play the most roles and have the greatest impact because of the tremendous deficiencies of the young Court struggling to establish itself and the well-resourced, thousands-strong coalition of NGOs that views the Court as its child and wishes it to grow into the court that they fought to bring into existence. The ICC needs the expertise, advocacy, and institutional support of NGOs to operate. The Coalition for the International Criminal Court and other prominent international NGOs—financially buoyed by the outpouring of monies from foundations—proactively sought to fill the needs of the ICC and through its role as central coordinator of NGO activity, effectively became the Court’s eyes and ears of civil society.