Cesare Emiliani established that the ice ages of the last half million years or so are cyclic phenomena, which gave strong support to the hypothesis of Milankovitch. He discovered the cycles when analyzing foraminifers from long deep-sea cores for their oxygen isotope composition (cores were from the Swedish Deep-Sea Expedition, from the Lamont collection and later from collections made at Miami). Emiliani’s method has become the standard procedure for interpreting the deep-sea record in terms of ocean and climate history. Emiliani introduced a time scale suggesting that the cycles are typically 40 000 years in duration, and he defended this scale for almost 20 years. He also thought that temperature was a more important influence on oxygen isotope variations of the ocean than the buildup and decay of northern hemisphere ice sheets. Both these notions proved incorrect. However, his insistence that the Milankovitch mechanism, in conjunction with ice dynamics and crustal response to loading, is the driving force behind the climate cycles of the Quaternary proved well founded.