Situated on the second level (piano nobile) of the Vatican Palace, overlooking the south side of the Belvedere Courtyard, are eight rooms or sale that comprised the papal apartment of the Spanish native, Pope Alexander VI (Rodrigo Borgia, born c. 1431; r. 1492-1503). These spaces once hosted powerful cardinals and heads of state for diplomatic or religious matters. They also served as Alexander VI's private living spaces. During meetings or meals with the Borgia pope, guests encountered a visual array of opulent fresco programs that included fictive tapestries along the lower half of the wall surface, vibrant narrative lunettes on the upper half, and lavishly gilded vault programs decorated by Bernardino Pinturicchio (1454-1513) and his workshop during 1492-94. Combining iconographic study, examination of primary source documents regarding court ceremony and use of the space, and architectural analyses of Roman palazzi from the period, this thesis offers the first sustained consideration of the multiple, and often overlapping, functions that the eight rooms of the Borgia apartment likely served during Alexander VI's pontificate. Such an effort is especially important as Alexander VI's apartment in the Vatican Palace represents the oldest surviving decorated papal apartment in Rome. Sustained consideration of how the pontiff and his court likely utilized the spaces offers an unparalleled opportunity to gain a greater understanding of early modern papal ceremony. As this study demonstrates, each of the rooms served multiple and interrelated functions dictated by ceremony, etiquette and architecture.