August 31 is the Feast Day.
Not much is known with certainty of Aidan's early life. He was born in Ireland and by reputation was very bright and very devout. Early in his career he was made bishop, but he resigned to become a monk of Iona, where he learned the values of prayer, study, self-discipline and almsgiving that shaped his future ministry.
While Aidan was living at Iona, King Oswald of Northumbria sent to Iona for a bishop to come and teach the Christian faith to his subjects. The first missioner sent from Iona returned frustrated and angry, saying the people of Northumbria were unteachable and barbaric. Aidan suggested that people who had never heard the Gospel needed to learn of it gradually, and that the approach of evangelists should be gentle. As a result of his spirit of humility and practical wisdom, Aidan was sent as bishop and missionary to the Saxons.
Aidan knew from the beginning he would need an isolated place for solitude and prayer to prepare for the great demands of his mission. In 625 he established a monastery under the Rule of Saint Columcille on the isle of Lindisfarne, which became known as Holy Island. The community was not allowed to accumulate wealth; surpluses were applied to the needs of the poor and the manumission of slaves.
From Lindisfarne Aidan made journeys on foot throughout the diocese, visiting his flock and establishing missionary centers. Aidan preached in Irish and the king provided the translation. To unbelievers he brought the hope of belief. To the newly converted he taught the value of prayer and scripture. He was indefatigable in tending to the welfare of children and slaves, and bought the freedom of many slaves from alms bestowed on him.
When Aidan received fine presents, he distributed them among the poor. In one story a king gave Aidan a fine horse laden with royal trappings. However, upon seeing a beggar on the road, Aidan gave the horse to the poor man. When the king heard the story, he questioned Aidan's judgment in giving away such a valuable gift. Aidan responded that Jesus Christ gave the gift of his life for us, and that surely the son of a mare is not more valuable than the Son of God.
The Venerable Bede wrote of Saint Aidan: "He neither sought nor loved anything of this world, but delighted in distributing immediately to the poor whatever was given him by kings or rich men. He traversed both town and country on foot, never on horseback, unless compelled by some urgent necessity. Wherever on his way he saw any, either rich or poor, he invited them, if pagans, to embrace the mystery of the faith; or if they were believers, he sought to strengthen them in their faith and stir them up by words and actions to alms and good works."
Aidan was a member of the Celtic branch of Christianity instead of the Latin branch, but his character and energy in missionary work won him the respect of Pope Honorius I and Felix of Dunwich.
Aidan's friend Oswine of Deira was murdered in 651. Twelve days later Aidan died, on 31 August, in the 17th year of his episcopate. He had become ill while at the Bamburgh castle and died leaning against the buttress of a church on a royal estate near Bamburgh.
The monastery he founded grew and helped found churches and other monasteries throughout the area. It also became a centre of learning and a storehouse of scholarly knowledge. Saint Bede the Venerable would later write Aidan's biography and describe the miracles attributed to him. Saint Aidan's feast day is on 31 August. Aidan was also call the Apostle Of the English, Unlike St Augustine who was the apostle of Kent.
From communio by Paul Zalonski