The main topic of this monograph is the design of a feedback control system for magnetic fields to guarantee the plasma equilibrium inside a tokamak with a prescribed position and shape. Modelling and control details are presented, allowing the non-expert to understand the control problem. Starting from equations of magneto-hydro-dynamics, all the steps needed for the derivation of plasma state-space models are enumerated. The basics of electromagnetics are frequently recalled. The control problem is then described beginning with control of current and position vertical and radial and progressing to more challenging shape control. The solutions proposed vary from simple PIDS to more sophisticated MIMO controllers.Wherever possible, the various topics are rounded out with results obtained through the authors contributions to experiments with actual tokamaks. Mathematical details which are outside the normal province of control engineers are presented in an appendix for the interested reader.