With his book "The Origin of Continents and Oceans," Alfred Wegener (1880-1930) created and established the theory of continental drift. From 1915 to 1929, four distinctly revised editions of this book were published. The fourth edition was repeatedly reprinted in the following years. This book commemorates Wegener's 125th birthday and 75th death anniversary, as well as the 25th anniversary of the Alfred Wegener Institute for Polar and Marine Research, by reproducing the first and fourth editions as faithful facsimiles. The more popular first edition includes Wegener's handwritten notes and excerpts. Additional features of this edition include an introduction by the editors, two indexes, lists of illustrations, and a modified bibliography.