In 1959, though just twenty-six years old and a graduate student, George B. Schaller shrugged off warnings of mortal danger and set off for the Belgian Congo to do what no other scientist had dared: study mountain gorillas, the real King Kong, by living alongside them. Boldly refusing arms and retinue, Schaller and his wife, Kay, established a home in the jungle and came to share the apes' rhythms and rules. After more than two years of immersive research - a groundbreaking methodology he would spend his life honing - Schaller transformed how the world viewed gorillas; they were not murderous brutes but tender creatures, and more like humans than any twentieth-century scientist had recognized. His mission to revolutionize our perceptions of wild animals would propel him across four continents and inspire generations of scientists. In Homesick for a World Unknown, Miriam Horn draws on thousands of pages from Schaller's journals and letters, globe-spanning interviews, and two journeys into the field with the legendary scientist himself to trace his emergence as the founding father of modern wildlife conservation. She probes what drives him to know Earth's wildest places and most fearsome creatures, beginning with a childhood upended by displacement and atrocity. Born in Berlin in 1933 to an American socialite married to a German diplomat during the Nazi era, the young Schaller was moved from one occupied country to another before finally arriving with his mother in the U.S. in 1947, as an enemy alien. It was in the Missouri woods that teenage George found a place of respite and at the University of Alaska that he found both his calling and a lifelong partner in Kay. In the decades following his work in the Congo, Schaller went on to conduct the earliest studies of Indian tigers, Serengeti lions, Brazilian jaguars, Chinese pandas, and Tibetan brown bears, meticulously cataloging their private lives. He navigated acute danger, violent conflict, and treacherous politics in pursuit of empathy for and preservation of creatures big and small. It was Schaller who first guided Jane Goodall on her chimp study in Tanzania and led Peter Matthiessen into Nepal in search of the snow leopard. And while remaking wildlife science, his impact went further still: he spurred the creation of vast national parks and partnered with local communities to protect the homes they share with these animals. A vivid and captivating account of the adventurous life of George B. Schaller, here is the definitive portrait of the man who dared to challenge us to rethink our place in the natural world.