This book aims to provide a concise and coherent introduction to the physics of particle accelerators. It is written for students at the graduate level in physics and provides the elements to tackle the main problems regarding cyclic particle accelerators. In particular, a thorough introduction is given on the topics of such machines. Phase focusing is also fully treated together with fundamental topics like synchrotron radiation and linear and nonlinear resonances. A chapter is devoted to rf linear accelerators and rf structures. The chapter on space charge effects deals with tune-shifts and beam-beam interactions. The final chapter treats both electron and stochastic cooling, thus rounding up the treatment of phase-space shrinkage introduced in the chapter on synchrotron.