The Forum, once the most central and sacred part of the ancient city of Rome, evolved over the course of centuries into a cluttered space at the threshold of the built-up city and its more rural periphery. Among the rubble of antique monuments--destroyed by earthquakes, flooding, or purposeful spoliation--livestock grazed at the site, giving it the appellation Campo Vaccino, or cow pasture, in the early modern period. Despite these obstacles, the Forum remained a vital part of the spiritual life of Romans after several of its structures were Christianized beginning in the sixth century. It became the province of the Catholic Church, and underwent a significant rehabilitation through papal patronage in the late sixteenth and seventeenth centuries. The seven churches ringing the Forum's periphery were restored or rebuilt over the course of about fifty years, allowing the patrons to harness the symbolism of the pagan and Christian past of the site to promote the glorious reviving Church. In this dissertation, I examine the Forum from a variety of vantage points, in order to reconstruct the antiquarian understanding of the site, its monuments, and history in the seventeenth century. The first chapter examines the historiography of the Forum and its churches, while outlining the issues at stake in the refashioning of this urban center. Chapter Two provides an overview of the Forum's history up to the sixteenth century. In Chapter Three, I consider the phenomenon of the Paleochristian Revival of the Counter-Reformation, and the ways in which it manifested itself at the Campo Vaccino. Chapter Four begins a series of case studies, organized by papacy, to elucidate the state of the Forum and its churches. Clement VIII Aldobrandini's direct patronage and other projects dating to his papacy initiated the wave of renovations that continued over the next several decades. The papacies of Paul V Borghese and Gregory XV Ludovisi are the subject of Chapter Five, when the urban environment at the edge of the Forum underwent new developments, in addition to works at the churches themselves. In Chapter Six, I focus on the two projects commissioned by Urban VIII Barberini: SS. Cosma e Damiano and SS. Luca e Martina, which demonstrate two very different approaches to ancient buildings. Finally, Chapter Seven considers works in the Campo Vaccino during the reign of Innocent X Pamphili, and the unification of these disparate renovations by the dramatic remaking of the central space by Alexander VII Chigi. These numerous projects carried out between 1592 and 1656 completely remade the Forum, renewing its historical importance in the city while highlighting its connection to Rome's dual history. The imperial and Early Christian past at the Forum now stood alongside the monuments of early modern Rome. The seventeenth century project added a new layer to the palimpsest of this eminently historical site. / Art History