This book investigates the role of Sir Robert Hart in China’s early engagement with Western international law, covering the period from Hart’s earliest days as Inspector General of the foreign-dominated Chinese Imperial Maritime Customs (CIMC) to his final years in China (1863-1908). Drawing on Hart’s personal records, particularly his diaries and correspondence with CIMC officials and various political figures, as well as Customs Service official publications, records of the British Foreign Office, Chinese official papers, newspapers, and other contemporary publications, the book focuses on Sino-foreign jurisdictional disputes in which Hart was involved. They are used as case studies to examine his role – and more broadly, that of the CIMC – in influencing contemporary perceptions in the West about China’s status vis-à-vis Western nation-states. Going beyond portraying Hart as a mere broker, the book delves into his complex and multi-faceted character. It examines his idiosyncratic approach to Qing engagement with the West, particularly focusing on his proposals for dealing with international institutions. While these proposals had the potential to strengthen China, they sought to do so largely on Western terms, ultimately undermining China's ability to function as an independent state. By analysing Hart's character and his engagement with Western international law, the author aims to provide a nuanced understanding of the complexities surrounding Qing China's interaction with the West. It highlights the ambivalence exhibited by both Qing and Western officials, emphasising the challenges and opportunities in negotiations based on Western legal principles. Contributing to discussion on whether international structures could be utilised to bolster Qing sovereignty, this book will provide insights for those researching Chinese history, diplomatic history and international relations, and international law.