In the Cathedral of Monreale, there is a particular spatial composition of the   
    presbyteral area
    
  
  
, consisting of a double volume, in some cases also called double   
    transept
    
  
  
.
It is this typology, unique in Sicily for Norman churches, which also distinguished the   
    Palermo Cathedral
    
  
  
, in its original layout, now appreciable only from the view of the external volumes.
The space of the sacred area of the Sanctuary is divided into two large rooms, distinct from the   
    church hall
    
  
  
 because of its higher position, connected to it by some steps.
The whole area is generically called the   
    Great Chancel
    
  
  
, and is effectively divided into three distinct parts: the larger central part, closer to the hall, is more properly called the   
    Presbytery
    
  
  
.
This is delimited by two narrow transverse spaces: the   
    Anti-Presbytery Floor
    
  
  
, towards the hall, and the   
    Post-Presbytery Floor
    
  
  
, connecting the side apses with the   
    Tribuna maggiore
    
  
  
 of the   
    central apse
    
  
  
. These spaces in Palermo Cathedral are identified with the ancient name of   
    Titulus
    
  
  
, corresponding to the presbytery of Monreale and   
    Antititulus
    
  
  
 with the space of the Post Presbytery. In Palermo Cathedral, the Titulus was the area designated for the Cathedral’s   
    Canons Titular
    
  
  
, who took their place in the   
    choir
    
  
  
. The bishop’s chair and the royal seat were located in this space. The cemetery area with the   
    sarcophagi
    
  
  
 of the kings and bishops were located on either side of the Titulus. Similarly, and still visible today, in Monreale, the choir is located in the space of the presbytery and the adjoining side parts are dedicated to containing the royal sarcophagi.