- Flavius Claudius Constantinus, a.d. 317–340, emperor of Rome 337–340 (son of Constantine I).
- born 1940, king of Greece 1964–74, in exile since 1967.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- official title Constantine XIII. born 1940, king of Greece (1964–73): went into exile when the army seized power in 1967. He was officially deposed in 1973 and Greece became a republic