The old Celtic Church of Scotland was brought to an end by two causes--internal decay and external change. Under the first head, notice must be taken of the encroachment upon the ecclesiastic element by the secular, and of the gradual absorption of the former by the latter. There was a vitality in the old ecclesiastical organisation, but it was weakened by the assimilation of the native Church to that of Rome in the seventh and eighth centuries, which introduced a secular element among the clergy; and the frequent Danish invasions, which may be described as the organised power of Paganism against Scottish Christianity, grievously undermined its native force. The Celtic churches and monasteries were repeatedly laid waste or destroyed, and the native clergy were compelled either to fly or take up arms in defence; the lands, unprotected by the strong arm of law, fell into the hands of laymen, who made them hereditary in their families, and ultimately nothing was left but the name of abbacy, applied to the lands, and that of abbot, borne by a secular lord. Under the second head--external change--may be noted the policy adopted towards the Celtic Church by the kings of the race of Queen Margaret. It consisted (1) in placing the Church upon a territorial in place of a tribal basis, in substituting the parochial system and a diocesan episcopacy for the old tribal churches with monastic jurisdiction and functional episcopacy; (2) in introducing the orders of the Church of Rome, and founding great monasteries as counter influences to the Celtic Church; (3) in absorbing the Culdees or Columban clergy into the Roman system, by first converting them from secular into regular canons, and afterwards by merging them in the latter order.[1] King David especially founded bishoprics and established cathedrals, equipped with the ordinary cathedral staff of deans, canons, and other functionaries, and monasteries equipped with representatives of the monastic orders. Thus the native Celtic Church, undermined by internal decay, was extinguished by external change and a course of aggression which rolled from St. Andrews until it reached the far-off shores of Iona. All that remained to speak of its vitality and beneficence to the people of Scotland consisted of the roofless walls of an early church, or an old churchyard with its Celtic cross; the names of the early pastors by whom the churches were founded, or the neighbouring wells at the old foundations, dedicated to their memory; the village fairs, stretching back to a remote antiquity, and held on the saint's day in the Scottish calendar; here and there a few lay families possessing the church lands as the custodiers of the pastoral staff or other relics of the founder of the church, and exercising a jurisdiction over the ancient "girth" or sanctuary boundary such as the early missionaries instituted in the days when might was right, and they nobly witnessed to the right against the might.