Animals, and our ever-changing relationship with them, have left an indelible mark on human history. Through an in-depth analysis of six truly transformative human-animal relationships, Fagan shows how our habits and our very way of life were considerably and irreversibly altered by our intimate bond with animals. Among other stories, Fagan explores how herding changed human behavior; how the humble donkey helped launch the process of globalization; and how the horse carried a hearty band of nomads across the world and toppled the emperor of China.