The presence of royal doors in Western medieval churches and cathedrals is a widely discussed topic in the literature, but less attention has been given to the iconography, function, and location of entrances reserved for royalty in Byzantine churches. Scholars had assumed that unless specifically indicated the main entrance into Byzantine churches was located on the west side of the edifice. In his important study on the palatine aspects of Cappella Palatina, Slobodan Ćurčić successfully challenged this claim and brought to our attention processional and programmatic concerns in determining the function of an entrance.1 He also pointed out the important role of the doors located on the flanking façades of the edifice. Following in the footsteps of my professor and mentor, albeit with considerably smaller feet, this chapter aims to provide further questioning of the function of entrances in Byzantine churches. More specifically, I examine the iconography, function, and significance of the south door of the fourteenth-century church of St. Demetrios, popularly known as Marko’s Monastery, for which it was the katholikon. I argue that the south door was intended for the entrance of the king (Figure 6.1).