Nomads have often been relegated to the margins in the histories of “civilizations,” their failures attributed to their adherence to nomadic traditions and their successes credited to their adoption of a sedentary lifestyle. Instead, Pamela Kyle Crossley presents a sweeping study of nomads, weaving their influence into the fabric of Eurasian civilization across space and time. Diverging from the common approach of treating Eurasian history as a collective of histories separated by region, in Hammer and Anvil, Crossley cuts across established civilizational borders to address the nomadic imprint on modernity. The application of the nomadic diaspora to the understanding of the transition from the medieval to early modern world is ambitious, but persuasive and original. Turkic and Mongol nomads take center stage in this book as Crossley delves into religious beliefs, traditions, technologies, and governance to argue how many sedentary political and cultural transformations originated from their nomadic rule. Wedged between a brief introduction and epilogue are eleven substantive chapters, separated into four parts, providing abundant evidence and insightful analysis.

Part one, “The Integrity of Eurasia,” lays the groundwork for the rest of the book, painting the landscape of Eurasia in both physical and metaphysical form. Crossley adopts the definition of Eurasia as “an east-west temperate zone” (p. 4) to describe the Eurasian world through six factors—topography, chronology, transaction, reticulation, horse vector, and nomads—which can be clearly divided into distinct medieval and early modern periods. From the network of roads to the domestication of the horse, the spread of material goods and cultural influences suggests a permeable Eurasia, with Central Asia playing a crucial role in the middle. This “interpermeability” also proves to be applicable to religions and philosophies. From prehistory, Eurasia was home to “light and dark cosmology,” later evolving into religions such as Buddhism, Christianity, and Islam as a result of the transfer of ideologies across Eurasia over time.

A permeable Eurasia serves as a backdrop for part two, “Steppe Power in Settled Medieval Eurasia,” which consists of three chapters examining Turkic rule. The long history of state building by Turkic groups is scattered across Eurasia, exemplified by regimes such as the Northern Wei (386–534) in the east and the Khazar Khaganate (650–969) in the west. While the start of the fifth century saw the blending of religion and conquest, leading to the creation of “confessional” states, the decentralization of these states later created opportunities that prompted a resurgence of steppe political order. Crossley points to the rise of Turkic rule in the Islamic world. The powerful Turkic mamluks wrested political control from the weakened Abbasid caliphate, restructuring governance based on their Turkic tradition of leadership. The Turkic Seljuk sultan allocated domains to members of his aristocratic lineage, who, in turn, endorsed the selection of the sultan, replicating Turkic political tradition (p. 90). Crossley emphasizes that this show of Turkic decentralization should not be viewed as a failure of state building, but rather as “a long-tested state pattern that accommodated both Turkic practices of shared political power and Islamic values of a monolithic moral authority” (p. 95).

Part three, “The Age of Far Conquest,” carries the narrative of nomadic importance from the perspective of the Mongols. From the start of the thirteenth century, Chinggis Khan enforced traditional nomadic political and military structures to conduct campaigns. Turkic militant groups were the driving force of his conquests, while his conquering of neighboring nomadic states such as Xixia and Kara Kitai led to the adoption and application of nomadic plural systems of law to the Muslim world. Toward the end of Chinggis's and the start of his son Ogedei's rule, the Mongol Empire observed the assimilation of nomadic systems such as imperial guards (keshig), the Mongol style of taxation, and the post network (yam). However, Crossley demonstrates that it was primarily Chinggis's successors who expedited the transition from the medieval to the early modern world. Chinggis's grandsons, the two Toluid brothers, Hulagu and Kublai, employed a mixture of governance tactics in their rule of Ilkhanate and Yuan China. They appeased the locals by being receptive to local traditions while also importing systems such as nomadic infrastructure for city building. Especially, the exchange of goods and knowledge between the two Toluid states contributed to a connected Eurasian world. The end of this section returns to the Turkic diaspora alongside their Mongol counterparts, touching on the Mamluk's efficient control over the Levant region through their maintenance of an oscillating tension between the realms of military and merchant, the Ottoman's observation of traditional Turkic practices such as fratricide, and the Turkic militant group's potent power under the Jochid rule in the Russian steppe.

While the previous two parts chronicled the influence of the Turkic and Mongol nomadic reigns, part four, “The Forge,” crucially questions the current scholarly understanding of the Eurasian transition and frames the nomadic narrative of the transition within the context of modernity. Crossley disputes the Eurocentric understanding of religion and science during this transition. The Mongol's policy on religion was not “tolerance” but rather imitative of Central Asian tradition, and likewise, the “idea of science” was not exclusive to Europe but prevalent during the postnomadic rule of Iran, Central Asia, and China. “Imitations of nationality” was the product of conquered peoples constructing their identities under nomadic rule facilitated by the restructuring of administrational institutions, new forms of literature and arts, and the spread of printing culture. And the gradual disintegration of old structures of authority such as religious transcendence and self-legitimating rulership was the consequence of the segmentation of governance under nomadic rule.

Expertly navigating the histories of East Asia, Central Asia, the Muslim world, and Christendom, Crossley accurately homes in on identical patterns of nomadic origin, offering a solid suggestion for the prevalence of nomadic influence in the shaping of the modern world. An ample supply of maps depicting the locations of nomadic regimes helps anchor the reader to the fast-paced text. The annotated notes at the end of each chapter show Crossley's efforts to take stock of diverse source material and provide additional reading that will prove to be a valuable guide to the text. It should appeal to not only Eurasian historians, but also anyone who works on global comparative history. Taken as a whole, Hammer and Anvil: Nomad Rulers at the Forge of the Modern World offers a valuable stimulus to both east and west Eurasian history.