Wladimir Köppen (1846–1940, originally from St. Petersburg), Alfred Wegener (1880–1930, originally from Berlin) and Milutin Milankovitch (1879– 1958, originally from Dalj/ then Austria-Hungary, today eastern Croatia) made very important contributions to paleoclimatology during the early years of the 20th century. Köppen described the global climate zonation, Wegener defined the continental drift during the Phanerozoic, using Köppen´s climate zonations applied to paleogeographic scenarios of the geological past, and Milankovitch introduced regularly changing orbital parameters as controls of past climatic changes providing a precise time scale for Glacials and Interglacials during the Quaternary. By combining their scientific efforts, they succeeded to change our understanding of Earth history in a fundamental way, each of them with their specific expertise and their wide scientific horizons.