The Monk Cosmas, Bishop of Maiuma and often called “The Hymnographer”, Author of Canons, was a native of Jerusalem. He was raised by the parents of Saint John of Damascus (Comm. 4 December) together with their son, and he received a fine education. When Saint Cosmas came of age, he set out to one of the monasteries of Palestine, where he attained reknown for monastic exploits. During a time of persecution against holy icons the Monk Cosmas, together with Saint John, came forth for the defense of Orthodoxy. In the year 743 Cosmas was made bishop of Maiuma. He died in old age (+ c. 787), leaving behind many canons (odes and hymns) for feastdays and a triode for four days of Holy Week.
Source: Menologion 3.0
Editor’s Note: The hymns of Cosmas were originally used to the Glory of God in the services at Jerusalem, but through the influence of Constantinople their use became universal in the Greek Orthodox Church. And such are the riches of the Holy Spirit spread throughout the whole world.
It is also significant that we are able to ascribe a personality to the composition of hmyns. There are many reknown composers of hymns, who were fountains gushing forth the wisdom of the Holy Spirit.