It is during this period, while Feidhlimidh and Cilline the anchorite appear as rival abbots, that a catastrophe is recorded by Tighernac in 737,[523] in which Failbe, son of Guaire, the heir of Maelruba of _Apuorcrosan_, was drowned in the deep sea with twenty-two of his sailors. The monastery founded by Maelruba at _Apuorcrosan_, now Applecross, had therefore remained intact. The word ‘hæres,’ or heir, is here the equivalent of the Irish word _Comharba_, pronounced coärb, signifying co-heir or inheritor,[524] which occasionally appears as applied to the heads of religious houses in Ireland during the preceding century, in connection with the name of its founder, and which now makes its first appearance in Scotland. In the Monastic Church in Ireland, when land was given by the chief or head of a family, it was held to be a personal grant to the saint or missionary himself and to his heirs, according to the ecclesiastical law of succession. Heirs of his body such a founder of a monastery, who was himself under the monastic rule, of course could not have; but, as we have seen, when the tribe of the land and the tribe of the patron saint were the same, the former supplied the abbacy with a person qualified to occupy the position; and, when they were different, the abbot was taken from the tribe to which the patron saint belonged. These were his ecclesiastical successors and co-heirs. As such they inherited the land or territory which had been granted to the original founder of the church or monastery, and as such they inherited, as coärbs, or co-heirs, his ecclesiastical as well as his temporal rights.[525] When the integrity of the monastic institutions in Ireland began to be impaired in the seventh century under the influence of the party who had conformed to Rome, the heads of the religious houses found it necessary to fall back more upon the rights and privileges inherited from the founders; and hence in this century the term of Coärb, in connection with the name of some eminent saint, came to designate the bishops or abbots who were the successors of his spiritual and temporal privileges, and eventually the possessor of the land, bearing the name of abbot, whether he were a layman or a cleric. Thus, at A.D. 590, the annals record the appointment of Gregory the Great to be coärb of Peter the Apostle, that is, bishop of Rome. At 606 we have the death of Sillan, son of Caimin, abbot of Bangor and ‘coärb of Comgall,’ who was its founder. In 654 we find the superior of the church of Aranmore called ‘coärb of Enda’ its founder; and in 680 the superior of the monastery at Cork is termed coärb of St. Barry, who founded it.[526] Here in 737 the abbot of the monastery at Apuorcrosan is termed the heir, that is coärb, of Maelruba, who founded it; and, as we shall see, the abbots of Iona became known under the designation of coärbs of Columcille. Twelve years afterwards a similar catastrophe