Saint Aidan

An Irishman, possibly born in Connacht, Aidan was a monk at the monastery on the island of Iona in Scotland.
The Roman Empire had spread Christianity into Britain, but due to its decline, Anglo-Saxon polytheism was seeing a resurgence in some parts. Oswald of Northumbria had been living at the Iona monastery as a king in exile since 616 AD. There he converted to Christianity and was baptised. In 634 he gained the crown of Northumbria, and was determined to bring Christianity to the mostly pagan people there.
Owing to his past at Iona, he requested missionaries from that monastery instead of the Roman-backed monasteries in England. At first the monastery sent a new bishop named Cormán, but he returned to Iona and reported that the Northumbrians were too stubborn to be converted. Aidan criticized Cormán's methods and was soon sent as a replacement in 635.
Aidan chose the island of Lindisfarne, close to the royal castle at Bamburgh, as his seat of his diocese. King Oswald, who spoke Irish, often had to translate for Aidan and his monks, who did not speak English at first. When Oswald died in 642, Aidan received continued support from King Oswine of Deira and the two became close friends.
An inspired missionary, Aidan would walk from one village to another, politely conversing with the people he saw and slowly interesting them in Christianity. According to legend, the king gave Aidan a horse so that he wouldn't have to walk, but Aidan gave the horse to a beggar. By patiently talking to the people on their own level Aidan and his monks slowly restored Christianity to the Northumbrian communities. Aidan also took in twelve English boys to train at the monastery, to ensure that the area's future religious leadership would be English.
In 651 a pagan army attacked Bamburgh and attempted to set its walls ablaze. According to legend, Aidan prayed for the city, after which the winds turned and blew the smoke and fire toward the enemy, repulsing them.
Aidan was a member of the Irish branch of Christianity instead of the Roman branch, but his character and energy in missionary work won him the respect of Pope Honorius.
Aidan's friend Oswine of Deira was murdered in 651. Twelve days later Aidan died, on August 31. He had become ill while at the Bamburgh castle and died leaning against the buttress of a church on a royal estate nearby.
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.

Saint Columba
Born in Ireland, he became a monk and was ordained as a priest. Tradition asserts that, sometime around 560, he became involved in a dispute with Saint Finnian over a psalter. Columba copied the manuscript at the scriptorium under Saint Finnian, intending to keep the copy. Saint Finnian disputed his right to keep the copy. The dispute eventually led to the pitched Battle of Cúl Dreimhne in 561, during which many men were killed. (Columba's copy of the psalter has been traditionally associated with an existing 7th century manuscript.) A synod of clerics and scholars threatened to excommunicate him for these deaths, but St. Brendan of Birr spoke on his behalf with the result that he was allowed to go into exile instead. Columba suggested that he work as a missionary in Scotland to help convert as many people as had been killed in the battle. He exiled himself from Ireland, to return only once again, several years later.

In 563 he traveled to Scotland with twelve companions, where according to his legend he first landed at the southern tip of the Kintyre peninsula, near Southend. However, being still in sight of his native land he moved further north up the west coast of Scotland. He was granted land on the island of Iona off the west coast of Scotland which became the centre of his evangelising mission to the Picts. However, there is a sense in which he was not leaving his native people, as the Irish Gaels had been colonizing the west coast of Scotland for the previous couple of centuries. Aside from the services he provided guiding the only centre of literacy in the region, his reputation as a holy man led to his role as a diplomat among the tribes; there are also many stories of miracles which he performed during his work to convert the Picts. He visited the pagan king Bridei at his base in Inverness, winning the king's respect. He subsequently played a major role in the politics of the country. He was also very energetic in his evangelical work, and, in addition to founding several churches in the Hebrides, he worked to turn his monastery at Iona into a school for missionaries. He was a renowned man of letters, having written several hymns and being credited with having transcribed 300 books. One of the few, if not the only, times he left Scotland after his arrival was toward the end of his life, when he returned to Ireland to found the monastery at Durrow. He died on Iona and was buried in the abbey he created.