We selected the cover pictures of these three important contributors to radioanalytical chemistry to acknowledge the many fine chemists and physicists who participated in the development of the discipline during the past century. During this time, applications of radioanalytical chemistry have proliferated. With the proliferation of applications has come an explosion of knowledge. This text both summarizes and explains that knowledge, from the point of view of many excellent practitioners of radioanalytical chemistry. The result is a text that serves dual functions: it is both a valuable resource for any practicing radiochemist and an instructional textbook for all radiochemists in training.