threat posed by the Vikings may have forced a union between the kingdoms of Dál Riata and the Picts under Kenneth mac Alpin, traditionally dated to 843. In 849, according to the Annals of Ulster the abbot of Iona once again took Columba's relics to Ireland, but the earliest version of the Chronicles of the Kings of Scots says that in the same year they were removed by Kenneth mac Alpin, to a church he had built, probably at Dunkeld, perhaps indicating that the relics were divided. The abbot of the new monastery at Dunkeld emerged as the Bishop of the new combined Kingdom of Alba, which would subsequently come to be known as the Kingdom of Scotland. Early monasticism While there were a series of reforms of monasticism in continental Europe and England, particularly those associated with Cluny in France from the tenth century, Scotland remained largely unaffected these until the late eleventh century. Physically Scottish monasteries differed significantly from those on the continent, and were often an isolated collection of wooden huts surrounded by a wall. The Irish architectural influence can be seen in surviving round towers at Brechin and Abernethy. Some early Scottish establishments had dynasties of abbots, who were often secular clergy with families, most famously at Dunkeld and Brechin; but these also existed across Scotland north of the Forth, as at Portmahomack, Mortlach, and Abernethy. Perhaps in reaction to this secularisation, a reforming movement of monks called Céli Dé (lit. "vassals of God"), anglicised as culdees, began in Ireland and spread to Scotland in the late eighth and early ninth centuries. Some Céli Dé took vows of chastity and poverty and while some lived individually as hermits, others lived beside or within existing monasteries. In most cases, even after the introduction of new forms of reformed monasticism from the eleventh century, these Céli Dé were not replaced and the tradition continued in parallel with the new foundations until the thirteenth century. Scottish monasticism played a major part in the Hiberno-Scottish mission, by which Scottish and Irish clergy undertook missions to the expanding Frankish Empire. They founded monasteries, often called Schottenklöster (meaning Gaelic monasteries in German), most of which became Benedictine establishments in what is now Germany. Scottish monks, such as St Cathróe of Metz, became local saints in the region. High Middle Ages Conversion of Scandinavian Scotland While the official conversion of Scandinavian Scotland took