Leo I, Prince of Armenia

Leo I
Լևոն Ա
Lord of Cilicia
Lord of Armenian Cilicia
Reign1129/1130–1137
PredecessorConstantine II
SuccessorThoros II (in 1144/45)
Bornc. 1080
DiedFebruary 14, 1140(1140-02-14) (aged 59–60)
Constantinople
SpouseBeatrix (Beatrice) of Rethel
Issueone/two unnamed daughter(s)
(?) Constantine
Thoros II
Stephen
Mleh I
Roupen
HouseRoupenians
FatherConstantine I
MotherAn unnamed great-granddaughter of Bardas Phokas

Leo I (Armenian: Լևոն Ա), also Levon I or Leon I, (unknown – Constantinople, February 14, 1140) was the fifth lord of Armenian Cilicia (1129/1130–1137).

He expanded his rule over the Cilician plains and even to the Mediterranean shores. In his time, relations between the Armenians and the Franks (the Crusaders), two former allies, were not always as courteous as before: a major cause of dissension between them was the ownership of the strongholds of the southern Amanus, and on the neighboring coasts of the Gulf of Alexandretta.

Leo was captured after being invited to a meeting by the Byzantine Emperor John II Comnenus, who had sworn a false promise of peace.