"Agent-Based Defeasible Control in Dynamic Environments" is the seventh volume of the DRUMS handbook series and addresses the topics of defeasible reasoning and the management of uncertainties in dynamic systems. This volume is the result of the successful ESPRIT projects DRUMS, which were conducted from 1989 to 1996. The focus is on understanding how both human and artificial agents are capable of reasoning about and controlling dynamic systems. The authors, Jan Treur and John-Jules Ch. Meyer, present a variety of models and formal approaches that enable the analysis and control of dynamic systems. The topics covered include logical approaches for agents and the formal analysis of agent-based and compositional systems. This volume is a valuable resource for researchers and practitioners dealing with the dynamics of thinking and control in complex environments.