Marcus Agrippa was the chief supporter of Octavian, the heir of Julius Caesar, in his rise to prominence as the first Roman Emperor Augustus. He also played a central role in the Augustan establishment of the new order of Empire, which replaced the late Republic. Agrippa’s land and sea victories were crucial for the success of Octavian, but it will be argued that his constructions were important instruments of change in this pivotal historical period. Consequently, all Agrippan works are investigated, whether for war or peace, and whether known from material remains or other evidence. Agrippan constructions in the West (Gaul and the Iberian Peninsula) are described in detail, and the others are described in more general terms. Previously, Agrippan constructions have either been included in biographies of Agrippa, and treated generally, or have been studied as particular works with detailed description, but little explanation. Also, constructions in towns with material remains or inscriptions have been extensively studied, but important works outside towns with fewer remains have been largely overlooked. Consequently, previous writers have represented Agrippa as a builder of monuments in towns and there has been little understanding of the nature or purpose of the totality of his works, and no proper account of them.

This dissertation examines links between architectural and colonial discourse in order to provide a new account of England’s fascination with the “all’antica” manner in the late-sixteenth and early-seventeenth centuries. I argue that the allure of classicism during this period was directly related to imperial ambitions awakened by the consolidation of the Scottish and English crowns. Seeking models for their nascent empire, architects and colonial “planters” looked to their own history as a Roman colony. Shared references to antiquity facilitated an unprecedented commerce between artistic and political discourse. Architects in England and colonizers abroad both fashioned themselves as the “new Romans,” reconceiving English identity as a product of Britain’s former subjugation. While classicism provided newly required symbols of empire, it also challenged traditional notions of “Englishness,” embroiling architects in cultural, political, and religious debates that transformed architecture and the status of architects.