There are five Pleistocene glacial/interglacial cycles recorded in deep-sea sediments from the last half million years, but only two classic interglacials are recognized on land. The dilemma stems from the different understanding and identification of glacials and interglacials in the geologic records on land and in the ocean. Only those intervals of warm climate that followed a major southward ice sheet advance and were accompanied by a deep penetrating oceanic transgression were recognized in their type areas of Northern Europe as true interglacials. Only those ice advances which left moraines farther south than younger ones were recognized as glacials. In contrast, all intervals reflecting exceptionally low global ice volume, high sea level and warm sea surface are taken as interglacials in the deep-sea record. Classic subdivisions are aligned with the glacial/interglacial cycles of marine isotope stage stratigraphies by proposed higher order units called supercycles (SC), bracketed by superterminations (ST). The Saalian supercycle (SC2) includes glacial cycles C, D and E composed of marine isotope stages MIS 6, 7, 8, 9, 10 and 11. The units MIS 7 to MIS 11 correspond to the Great (Gross) Interglacial, estimated from the early geologic considerations to be about 240 millennia long [Penck and Brückner, 1909. Die Alpen im Eiszeitalter, vols. 1-3. Christian-Herman Tauchnitz, Leipzig] and determined from astronomic computations to last 235 millennia [Milankovitch, 1941. Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem. Académie Royale Serbe Editions Speciales Section des Sciences Mathématiques et Naturelles, Tome CXXXIII. Stamparija Mihaila Curcica, Beograd, 633pp.). The current high precision radiometric dating fully confirms the accuracy of Milankovitch's determination and the pivotal role of orbital mechanisms in Pleistocene climate change.