Y Gododdin does not remark on the Picts as pagans. Conversion of the Pictish élite seems likely to have run over a considerable period, beginning in the fifth century and not complete until the seventh. Recent archaeological work at Portmahomack places the foundation of the monastery there, an area once assumed to be among the last converted, in the late sixth century. This is contemporary with Bridei mac Maelchon and Columba. The process of establishing Christianity throughout Pictland will have extended over a much longer period. Pictland was not solely influenced by Iona and Ireland. It also had ties to churches in England, as seen in the reign of Nechtan mac Der Ilei. The reported expulsion of Ionan monks and clergy by Nechtan in 717 may have been related to the controversy over the dating of Easter, and the manner of tonsure, where Nechtan appears to have supported the Roman usages, but may equally have been intended to increase royal power over the church. Nonetheless, the evidence of place names suggests a wide area of Ionan influence in Pictland. Gaelic monasticism 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