This chapter presents a brief historical review of the major developments in the area of modern control systems. It discusses the development of classical control and its evolution into modern and robust control. Applied control engineering is the engineering discipline that applies control theory to design systems with predictable behaviors. One of the aspects of control systems that has received considerable attention is that of developing efficient and stable computational algorithms. In control system design, the responses of system outputs to the system inputs are important to the engineers. The control engineers often try to determine the system response by using a mathematical model that represents the system behavior. The subject of computer-aided control system design is occupying an increasingly important place in automatic control engineering, and has become a necessary part of the fundamental background of control engineers prior to control applications.