How did Japanese Zen emerge from a secluded feudal tradition to become a vital force in a modern nation-state and colonial empire? How did this transformation help forge a Buddhist world across continents and oceans?In this landmark study, Aihua Zheng elucidates the career of Zen abbot Shaku Soen (1860-1919), the foundational figure of Western Zen, alongside modern developments within the Rinzai tradition and monastic institutions. She also traces Japanese Buddhists' transnational engagements, from pan-Asian exchanges that fueled domestic revivals to collaborations with Theravadins and Vedantins that introduced Buddhism to Western audiences. These foundations directly shaped modern Buddhism and the global Zen boom-echoing all the way to figures such as Thich Nhat Hanh-and ultimately explain why Soen and his Engakuji followers, including D. T. Suzuki, still provoke intense debate over their legacies.