church was increasingly influenced by the Roman form of Christianity. The careers of St. Wilfred (active from the 660s until his death in 709), abbot of the monastery at Ripon and Bishop of Northumbria, and Benedict Biscop (c. 628–690), founder of the monasteries of Jarrow and Wearmouth, intensified ties with Rome. Wilfred was the major spokesman for the Roman case at the Synod of Whitby in 664, which was called by king Oswiu of Northumbria to decide which form of observance would be used in his kingdom, and where he decided in favour of the Roman form of tonsure and of calculating Easter. In this period the Kingdom of Northumbria was expanding into what is now Lowland Scotland. A bishopric established at Abercorn in the region of West Lothian, is presumed to have adopted Roman forms of Christianity after the Synod of Whitby. However, the Pictish victory at the Battle of Dunnichen in 685, ended the Northumbrian dominance of the region and the Bishop and his followers were ejected. Nechtan mac Der-Ilei, king of the Picts from 706, seems to have attempted to establish links with the church in Northumbria. Before 714 he wrote to Ceolfrith, abbot of Wearmouth, asking for a formal refutation of the Irish position over the calculation of the date of Easter and for help in building a stone church "in the manner of the Romans". A. A. M. Duncan has suggested that there was a "Romanising group" among Nechtan's clergy, perhaps led by Bishop Curitan, who took the name Latin name Boniface. This is also suggested by the presence of a church at Rosemarkie in Ross and Cromarty, dedicated to St Peter, seen as the first Bishop of Rome, by the early eighth century, and subsequent similar dedications in Pictish territory. By the mid-eighth century, Iona and Ireland had accepted Roman practices. Iona's place as the centre of Scottish Christianity was disrupted by the arrival of the Vikings, first as raiders, then as conquerors. Iona was sacked by Vikings 795 and 802. In 806 68 monks were killed and the next year the abbot withdrew to Kells in Ireland, taking the relics of St. Columba with him. There were periodic returns of abbots and relics, often ending in more massacres. Orkney, Shetland, Western Isles and the Hebrides eventually fell to the Pagan Norsemen, curtailing the influence of the church in the Highlands and Islands. The