This thesis provides a reassessment of the theory of magnificence in light of the related social virtue of splendour. It aims to highlight how magnificence, when applied to private palaces, extended beyond merely the exterior to include the interior as a series of spaces where virtuous expenditure could and should be displayed. The thesis examines the Florentine Renaissance palace from three main perspectives. First, it explores the application of the classical theory of magnificence on fifteenth century ideas of decorum. Second it assesses the way such theories removed the inhibitions to build and provided patrons with the motivation to construct private palaces. Third, it considers the way these theories shaped contemporary views on the layout and furnishing of interiors by analysing the empirical evidence that survives for interiors belonging to a range of wealthy Florentines. Using unpublished inventories, together with select examples of ricordanze and surviving domestic objects, this project provides a wider understanding of the Renaissance urban palace. It demonstrates the ideas available to those who experienced these buildings, and reinstates what are often treated today as primarily decorative objects in their original domestic settings.