In the past decade, the number of monographs on the Mongol Empire has risen exponentially. Most of these works have focused on the empire as whole, or on a specific khanate. This new material has given us a much wider perspective on the Mongol Empire, and, indeed, our knowledge of how the empire maintained an interconnected identity despite rivalries has never been greater. Nonetheless, our understanding of the Mongol Empire still tends to be at the imperial level (whether the entire empire or just the regional khanates). And rarely has there been a study focusing on a region within one of the successor khanates after the Mongol Empire splintered in 1260. Thus, David M. Robinson's Empire's Twilight: Northeast Asia under the Mongols is a very welcome addition to the study of the Mongols.

Northeast Asia in any context remains a large slice of the empire. Nonetheless, a focus on a particular part of the Yuan Empire provides insight into other aspects of the empire—particularly toward the end of the Yuan dynasty. For the purpose of this monograph, Northeast Asia includes Koryo, Liaodong, Shandong, and the territory northeast of present-day Beijing. The focal point of the study is how the Red Turban rebellions, a Han anti-foreigner millenarian movement, affected the Yuan Empire. Robinson, however, approaches them from the perspective of the Mongol state rather than the traditional approach in Chinese history. He also considers the impact of the Red Turbans on Northeast Asia—largely a non-Han area. Robinson gives particular emphasis to Korean influence in the Yuan Empire, with a thorough study of the relations between Koryo and the Mongol court, as well as the political and cultural influence that Korean and Mongolian queens had on other courts. Nor does Robinson ignore the transplanted Korean populations in Liaodong and elsewhere in the Yuan Empire.

The book progresses through eight chapters, in addition to an introduction and epilogue, all facilitated by dynastic charts and three nicely detailed maps. Chapter 1 sets the scene with the original Mongol conquest of the region and the subsequent integration of the region. Rather than simply viewing it through political and military arrangements, Robinson does justice to the cultural and economic factors as well. Chapter 2 argues that the collapse of the Yuan was not a foregone conclusion in the mid-fourteenth century, yet also traces the rise and spread of the Red Turban rebellion. In this, it is an excellent primer for the aforementioned rebellion. Chapter 3 focuses on Koryo's place in the empire, while chapters 4 and 5 focus on the entry of the Red Turbans into northeast Asia and Koryo's response. Chapters 6 and 7 then examine the impact of the Red Turban Wars within the eastern subregion of Northeast Asia. Chapter 8 concludes the book with an examination of the impact of the Red Turban rebellion on the Mongol Empire as a whole—the Yuan Empire and beyond—followed by an epilogue that considers the Red Turbans in retrospect or rather how they were remembered.

In summary, Empire's Twilight is a very good book and will remain an important and standard work for years to come. Robinson's use of not only Chinese, Korean, and Japanese primary sources, but also Korean and Japanese secondary scholarship sets it apart from many other works on the Mongols. He incorporates new scholarship without overlooking older studies, while introducing or reintroducing sources that have been underutilized.

If there is any inconsistency, it is that although the stated theme of the book is Northeast Asia, the emphasis is usually on Korea under Mongol rule. This is not necessarily a bad thing, as Korea's position in the Mongol Empire is often underappreciated. Robinson does an excellent job in highlighting Korean influence and the Korean court's relations with the Yuan government. To be fair, Robinson does mention the families of the brothers of Chinggis Khan (whose patrimonies were in eastern Mongolia and Manchuria) at times, but he does not go into great detail about their activities in Northeast Asia, nor does he really discuss events in Mongolia in any detail in the final years of the Yuan Empire. Granted, Mongolia is not part of Robinson's definition of Northeast Asia. Nevertheless, considering the antipathy that the Mongols of Mongolia had toward the Yuan, it may have shed some light on the events. Still, the omissions appear to have more to do with the lack of data from sources rather than intentional neglect. Ultimately, the focus he places on Korea and Northeast Asia is a welcome addition to the study of the Mongol Empire thus making Empire's Twilight a book that every scholar of the Mongol Empire and early modern China or Korea should have in his or her library.