Provides a brief introduction to the concept of plate tectonics. Highlights some of the people and discoveries that have advanced the development of the theory and traces its progress since its proposal. Fully illustrated with extraordinary color photos and maps. Chapters: historical perspective; developing the theory (ocean floor mapping, magnetic stripping and polar reversals, magnetic stripes and isotopic clocks); understanding plate motions; "Hotspots": mantle thermal plumes; some unanswered questions; plate tectonics and people. References.