For thirty years historians of architecture have believed that the form of the domed rotunda designed by Diego Siloe for the cathedral of Granada was determined by its function as an imperial mausoleum for Charles V. This architectural innovation was purportedly stimulated by a decision made by the emperor in 1526 to be interred in the cathedral rather than in the Royal Chapel of Granada, burial site of his grandparents, Ferdinand and Isabella. The author demonstrates that, on the contrary, the emperor remained faithful to the traditions of his ancestors in this respect. His wishes concerning his burial in the Royal Chapel were respected by his son, Philip II, at least until Philip’s return from Flanders to Spain in 1559. Accordingly, another explanation for the striking form of the cathedral must be sought, and the generally held view that the Escorial was founded as a mausoleum for Charles V as early as 1558-1559 must be questioned. © 1992, The Society of Architectural Historians. All rights reserved.