Constantine I, King of Armenia

Constantine III. (Armenian Կոստանդին Ա; * 1278, † 1308) was from 1298 to 1299 King of the Armenian Kingdom of Cilicia. He was a son of Leo III. and Keran ( Kir Anna ), daughter of Prince Hethum of Lambron and belonged to the dynasty of the Hethumiden.

Constantine helped his brother Sempad 1296, to take over power in the kingdom, as their brothers Hethum II and Thoros III. were on a trip to Constantinople Opel to Rita of Armenia, a sister of the four, with Michael IX. Palaiologos, married to the co-emperor Andronikos II.

Two years later, Constantine turned against Sempad and freed Hethum, who had been imprisoned in the fortress of Sempad Partzerpert and blinded by cauterization partially. Constantine took power for a few months while Hethum was recovering from the effects of his captivity and glare. Shortly after Hethum had ascended the throne in 1299, Constantine was again the Creator of a conspiracy that was aimed Sempad to bring back to power. Hethum sent his two treacherous brothers to Constantinople Opel into exile.