The third edition of this well-received book is a readable introduction to the world of particle physics. It bridges the gap between traditional textbooks on the subject and popular accounts that assume little or no background knowledge. Carefully revised and updated, this edition covers all of the important concepts in our modern understanding of particle physics. The theoretical development of the subject is traced from the foundations of quantum mechanics and relativity through to particle discoveries and the formulation of modern string theory. It includes a full description of the prospects for the Large Hadron Collider at CERN, which will allow many key ideas to be tested. The book is intended for anyone with a background in the physical sciences who wishes to learn more about particle physics. It is also valuable to students of physics wishing to gain an introductory overview of the subject.