This dissertation demonstrates that there was an unprecedented expansion of Rajput-governed “little kingdoms” under the aegis of the Mughal Empire in the seventeenth century. The Rajputs, originating primarily from northwestern India, were elite Hindu upper-caste itinerant warriors. Rajputs belonging to notable clans served as administrative rank holders (manṣabdār) in the Mughal army and played key roles in battles that extended the frontiers of the empire. In addition to their military duties, these Rajput rank holders were assigned lands where they were responsible for the civil and revenue administration on behalf of the Mughal state. This dissertation examines the proliferation of Rajput claimants to kingship in early modern India in these hinterland agrarian subdistricts, and argues that Mughal territorial expansion directly cemented Rajput political authority in northwestern and central India. Indeed, several “little kingdoms” that the Rajput rank-holder kings settled survived the Mughal, Maratha, and British empires, and the descendants of those ruling families, their clan members, and their supporters remain elites and retain caste and political leadership to this day, despite the formal abolition of kingship in India in 1971. “Serving Empire, Building Kingdoms” shows that Rajput kingship flourished and transformed through a close engagement with the Mughal state and its apparatuses. The central question animating the project is how Hindu kingship evolved under the Islamicate Mughal Empire. Following the Mughal conquest of north India (1526), the Mughal emperor became the subcontinent’s sovereign authority, Padshah. This dissertation shows how Rajput warriors ascended the ranks of the Mughal nobility, and became hereditary rulers or “little kings” in the hinterlands. They took on the mantle of Raja (king), a durable template embedded in Sanskrit and Brahminical traditions. Rajput kingship was characterized by an emphasis on masculinity, combining Mughal courtly etiquette, ideals of chivalry, and a normative performance of the caste-based code of kshatriya dharma (warrior duty). In this way, Islamic rule in South Asia paradoxically served as a cradle for Hindu kingship. By analyzing the infrastructural, ideological, religiopolitical, and economic factors that reinforced Rajput kingship in the Mughal Empire, this dissertation offers a ground-up study of the Mughal Empire’s facilitative role in the crystallization of local power. Specifically, this dissertation examines one such instantiation of Rajput ascendancy—the founding of little kingdoms in northwestern and central India by Mahesdas (d. 1647), a scion of a minor branch of the prestigious Rathor family, and the subsequent administrative infrastructure and governance provided by his successors. To provide a comprehensive study of Rajput state formation in Mughal hinterlands, this dissertation turns to a combination of imperial sources in Persian, as well as materials in English and Sanskrit and an array of vernacular languages including Marwari, Braj, Hindi, Dingal, Malvi, and Pingal. Sources include Persian Mughal chronicles, courtly records, biographical compilations, land grants, poetry, newsletters, Marwari and Malvi chronicles on Rajput kingdoms, local administrative records, land grants, stone and copper-plate inscriptions, Rajput courtly literature in Braj, martyrological and heroic works in Dingal and Pingal, translated Sanskrit treatises, as well as British colonial-era ethnographic records, visual materials, built landscapes, field notes, and oral histories collected from central India and Rajasthan. Thus, besides standard sources in imperial and regional sources, “Serving Empire, Building Kingdoms,” foregrounds local texts and tales in marginal languages hitherto neglected in academic histories, bringing the little-known grassroots politics of the hinterlands to life. Undergirded by this multilingual archive, this work makes three key contributions to the study of South Asian history. First, it challenges the conventional position that local autonomy fragments empires. Rather, this dissertation shows that the proliferation of Rajput kingdoms expedited the consolidation of Mughal authority over the empire’s hinterlands and establishes how Mughal and Rajput political authority and ideologies of rule mutually reinforced each other in the localities. Indeed, Rajput rulers in the hinterlands consciously nested their claims to kingship within Mughal sovereignty. Next, this dissertation shows how Rajput kingship thrived under Islamic sovereignty. Successful Rajput Mughal rank-holder kings developed a version of kingship in the Mughal hinterlands that was simultaneously predicated on warrior-caste leadership and Mughal sovereignty. Whilst Hindu sacral authority provided a claim over kingship for Rajput military officers, Mughal legitimacy simultaneously afforded the necessary administrative power to enact, perform, and uphold kingship. The Mughal rank-holding system, this dissertation shows, was the bedrock for this political arrangement, even though the little kings’ kingship was largely unacknowledged in imperial sources. Third, “Serving Empire, Building Kingdoms” reorients Mughal historiography’s gaze from the imperial center to the political transformations brewing in the hinterlands. Contrary to the mainstream view that Mughal decline in the eighteenth century spurred the creation of regional successor states, this project shows that subordinate kingdoms with delineated systems of governance already operated in the Mughal hinterlands.