Namesakes

Bishops of Rome and the Popes: 1 antipope, 1 pope
Constantine (a.k.a. Constantinus)   708-715  
Constantine II (a.k.a. Constantinus)   767-768  
Roman and Byzantine Emperors: 12 emperors
Emperor Flavius Valerius Aurelius Constantinus (a.k.a. Constantinus)   306-337  
Emperor Flavius Claudius Constantinus (a.k.a. Constantinus)   337-340  
Emperor Heraclius Novus Constantinus (a.k.a. Constantinus)   641  
Emperor Constantinus Heraclius   641  
Emperor Constantinus   668-685  
Emperor Constantinus   741-775  
Emperor Constantinus   780-797  
Emperor Constantinus Porphyrogenitus   913-959  
Emperor Constantinus   1025-1028  
Emperor Constantinus Monomachus   1042-1055  
Emperor Constantinus Ducas   1059-1067  
Emperor Constantinus Palaeologus Dragases   1449-1453  
Saints: 1 saint
Saint Constantine the Great (a.k.a. Constantinus)   c. 272-337