In an era of warming climate, the study of our ice age past is more important than ever. In this Very Short Introduction, Jamie Woodward examines the Great Ice Age of the Quaternary Period. Considering evidence gathered from the continents, the oceans, and the ice cores, he examines the remarkable environmental shifts that repeatedly transformed the landscapes and ecosystems of the past. By exploring the history of ideas, the contributions from leading figures of the time and the key discoveries in the study of our glacial past, he sets out the human stories behind it all.