Iona, Or Icolmkill, called also I or Hy, a small island of the inner Hebrides, situated in lat. 56° 22' N, Ion. 6° 25' W., 9 m. S. W. of Staffa, and separated from the island of Mull by a channel 1 1/4 m. wide, called the sound of I or of Icolmkill. It is embraced within the parish of Kiltinichen and county of Argyle, and is 3 m. long by 1 1/2 m. broad; pop. about 300. It has an irregular surface of moorland, rising in places to 400 ft. About 600 acres of the island are under cultivation, producing barley and potatoes, but the chief occupation of the inhabitants is rearing black cattle and fishing. There is a small village, containing two churches, 40 or 50 detached cottages, and a school. - The island was given by the Pictish king Bridius in 563 to St. Columba (hence the name Icolmkill, the island of Columba of the cell), who founded there a celebrated monastery. Previous to his time the island was the chief seat of the rites of druidism. He established a college, which acquired great wealth and increased in influence till the time of the reformation.

The Culdees controlled it until the beginning of the 13th century, when they were driven out by those who acknowledged the authority of Rome. A nunnery established on the island about this time continued till 1543, when Anna Macdonald, the last prioress, died. The religious establishment was altogether broken up by the act of the Scotch parliament (1560) abolishing all religious houses. The island then passed into the hands of the McLeans, but is now the property of the duke of Argyll. - Iona is said to have had at one time 360 stone crosses, resembling those of Ireland, but most of them were destroyed by Puritan zeal, and only four now remain. Sepulchral remains cover the island, both in the shape of cairns and of stone monuments of all kinds, Iona having been considered from time immemorial a sacred island. An old prophecy declared that seven years before the end of the world a second'deluge would drown all nations, but that St. Columba's isle would swim above the flood; and this tradition made it the chosen cemetery of kings.

Numbers of Scotch, Irish, Norwegian, and even French kings were buried there, the last of whom is said to have been the famous Macbeth. Among the principal ruins are the church of St. Mary, a cruciform building with a square tower about 75 ft. high, dating from the beginning of the 13th century; St. Mary's nunnery, built in the 12th; and St. Oran's chapel, probably in the 11th.

Ruins of St. Mary's Church.