I have written this book to fulfill a need which exists for a short yet reasonably comprehensive history of geomorphology. I do not neglect the monumental volumes being produced by Chorley, Beckinsale and Dunn (1964, 1973), but the first of these volumes is now out of print and the second is devoted, very necessarily, to a biography of W.M.Davis. The complementary third volume on Davis's contemporaries, and the fourth volume on the period since 1945 have not yet appeared (at the time of writing). The two existing books are excellent reference volumes, and all geomorphologists, including this one, are greatly in debt to them, but they are daunting and expensive to the hard-pressed student who needs a brief guide to the main ideas.