The original form of the name boa was Hy, or I, the Irish for Island. By Adamnan in his Life of St Columba it is called Ioua insula, and the present name Iona is said to have originated in some transcriber mistaking the u in Ioua for n. It also received the name of Hii-colum-kill (Icolmkill), that is, “the island of Columba of the Cell,” while by the Highlanders it has been known as Innis nan Druidhneah (“ the island of the Druids “). This last name seems to imply that lona was a sacred spot before St Columba landed there in 563 and laid the foundations of his monastery. After this date it quickly developed into the most famous centre of Celtic Christianity, the mother community of numerous monastic houses, whence missionaries were despatched for the conversion of Scotland and northern England, and to which for centuries students flocked from all parts of the north.

After St Columba’s death the soil of the island was esteemed peculiarly sanctified by the presence of his relics, which rested here until they were removed to Ireland early in the 9th century. Pilgrims came from far and near to die in the island, in order that they might lie in its holy ground; and from all parts of northern Europe the bodies of the illustrious dead were brought here for burial. The fame and wealth of the monastery, however, sometimes attracted less welcome visitors. Several times it was plundered and burnt and the monks massacred by the heathen Norse sea-rovers. Late in the 11th century the desecrated monastery was restored by the saintly Queen Margaret, wife of Malcolm Canmore, king of Scotland; and in 1203 a new monastery and a nunnery were founded by Benedictine monks who either expelled or absorbed the Celtic community.

In 838 the Western Isles, then under the rule of the kings of Man, were erected into a bishopric of which Iona was the seat. When in 1098 Magnus III., “Barefoot,” king of Norway, ousted the jarls of Orkney from the isles, he united the see of the Isles (Sudreyar, “ the southern islands,” with that of Man, and placed both under the jurisdiction of the archbishopric of Trondhjem. About 1507 the island again became the seat of the bishopric of the Isles; but with the victory of the Protestant party in Scotland its ancient religious glory was finally eclipsed, and in 1561 the monastic buildings were dismantled by. order of the Convention of Estates.

The existing ancient remains include part of the cathedral church of St Mary, of the nunnery of St Mary, St Oran’s chapel, and a number of tombs and crosses. The cathedral dates from the 13th century; a great portion of the waIls with the tower, about 75 ft. high, are still standing. The choir and nave have been roofed, and the cathedral has in other respects been restored, the ruins having been conveyed in 1899 to a body of trustees by the eighth duke of Argyll. The remains of the conventual buildings still extant, to judge by the portion of a Norman arcade, are of earlier date than the cathedral. The small chapel of St Oran, or Odhrain, was built by Queen Margaret on the supposed site of Columba’s cell, and its ruins are the oldest in lona. Its round-arched western doorway has the characteristic Norman beak-head ornamentation. Of the nunnery only the chancel and nave of the Norman chapel remain, the last prioress, Anna (d. 5543), being buried within its walls. The cemetery, called in Gaelic Reilig Oiran (“ the burial-place of kings “), is said to contain the remains of forty-eight Scottish, four Irish and eight Danish and Norwegian monarchs, and possesses a large number of monumental stones. At the time of the Reformation it is said to have had 360 crosses, of which most were thrown into the sea by order of the synod of Argyll. Many, however, still remain, the finest being Maclean’s cross and St Martin’s. Both are still almost perfect, and are richly carved with Runic inscriptions, emblematic devices and fanciful scroll work. Of Columba’s monastery, which was built of wood, nothing remains.