Without money, terrorists cannot function as organizations and cannot conduct attacks. Yet the questions remain, how vulnerable are terrorists to financial disruptions? Can governments put pressure on their finances in meaningful ways or are they too resilient and adaptive to be affected by state actions? These and other questions about terrorism financing are vigorously debated by scholars and policymakers, particularly since the attacks of September 11th 2001 . While there is a growing literature on policy issues, strategies, and countermeasures, states must first understand their enemies before developing strategies to defeat them. So, instead of focusing on the state response, this book asks a more foundational question: How do different terrorist groups actually raise money? What are their budgets? What do their portfolios look like? How have they changed over time? What are the advantages and disadvantages of different sources of financing? The book includes case studies of 11 different terrorist groups or sets of groups within a country. It is clear that each group has a different portfolio tailored to their needs and their environment and this makes countering terrorist financing more challenging for the state. This topical book will be required reading for all students and scholars interested in terrorism financing as well as those working in government agencies tasked with combating terrorist groups and their financial resources.