Anglo-Saxon kingdoms in the late 7th century
During Wilfrid's lifetime Britain and Ireland consisted of a number of small kingdoms. Traditionally the English people were thought to have been divided into seven kingdoms, but modern historiography has shown that this is a simplification of a much more confused situation. A late 7th-century source, the Tribal Hidage, lists the peoples south of the Humber river; among the largest groups of peoples are the West Saxons (later Wessex), the East Angles and Mercians (later the Kingdom of Mercia), and the Kingdom of Kent. Smaller groups who at that time had their own royalty but were later absorbed into larger kingdoms include the peoples of Magonsæte, Lindsey, Hwicce, the East Saxons, the South Saxons, the Isle of Wight, and the Middle Angles. Other even smaller groups had their own rulers, but their size means that they do not often appear in the histories. There were also native Britons in the west, in modern-day Wales and Cornwall, who formed kingdoms including those of Dumnonia, Dyfed, and Gwynedd.
Between the Humber and Forth the English had formed into two main kingdoms, Deira and Bernicia, often united as the Kingdom of Northumbria. A number of Celtic kingdoms also existed in this region, including Craven, Elmet, Rheged, and Gododdin. A native British kingdom, later called the Kingdom of Strathclyde, survived as an independent power into the 10th century in the area which became modern-day Dunbartonshire and Clydesdale. To the north-west of Strathclyde lay the Gaelic kingdom of Dál Riata, and to the north-east a small number of Pictish kingdoms. Further north still lay the great Pictish kingdom of Fortriu, which after the Battle of Dun Nechtain in 685 came to be the strongest power in the northern half of Britain. The Irish had always had contacts with the rest of the British Isles, and during the early 6th century they immigrated from the island of Ireland to form the kingdom of Dál Riata, although exactly how much conquest took place is a matter of dispute with historians. It also appears likely that the Irish settled in parts of Wales, and even after the period of Irish settlement, Irish missionaries were active in Britain.
Christianity had only recently arrived in some of these kingdoms. Some had been converted by the Gregorian mission, a group of Roman missionaries who arrived in Kent in 597 and who mainly influenced southern Britain. Others had been converted by the Hiberno-Scottish mission, chiefly Irish missionaries working in Northumbria and neighbouring kingdoms. A few kingdoms, such as Dál Riata, became Christian but how they did so is unknown. The native Picts, according to the medieval writer Bede, were converted in two stages, initially by native Britons under Ninian, and subsequently by Irish missionaries.
The main sources for knowledge of Wilfrid are the medieval Vita Sancti Wilfrithi, written by Stephen of Ripon soon after Wilfrid's death, and the works of the medieval historian Bede, who knew Wilfrid during the bishop's lifetime. Stephen's Vita is a hagiography, intended to show Wilfrid as a saintly man, and to buttress claims that he was a saint. The Vita is selective in its coverage, and gives short shrift to Wilfrid's activities outside of Northumbria. Two-thirds of the work deals with Wilfrid's attempts to return to Northumbria, and is a defence and vindication of his Northumbrian career. Stephen's work is flattering and highly favourable to Wilfrid, making its use as a source problematic; despite its shortcomings however, the Vita is the main source of information on Wilfrid's life. It views the events in Northumbria in the light of Wilfrid's reputation and from his point of view, and is highly partisan. Another concern is that hagiographies were usually full of conventional material, often repeated from earlier saints' lives, as was the case with Stephen's work. It appears that the Vita Sancti Wilfrithi was not well known in the Middle Ages, as only two manuscripts of the work survive.
Bede also covers Wilfrid's life in his Historia ecclesiastica gentis Anglorum, but this account is more measured and restrained than the Vita. In the Historia, Bede used Stephen's Vita as a source, reworking the information and adding new material when possible. Other, more minor, sources for Wilfrid's life include a mention of Wilfrid in one of Bede's letters. A poetical Vita Sancti Wilfrithi by Frithegod written in the 10th century is essentially a rewrite of Stephen's Vita, produced in celebration of the movement of Wilfrid's relics to Canterbury. Wilfrid is also mentioned in the Anglo-Saxon Chronicle, but as the Chronicle was probably a 9th-century compilation, the material on Wilfrid may ultimately have derived either from Stephen's Vita or from Bede. Another, later, source is the Vita Sancti Wilfrithi written by Eadmer, a 12th-century Anglo-Norman writer and monk from Canterbury. This source is highly influenced by the contemporary concerns of its writer, but does attempt to provide some new material besides reworking Bede.
Many historians, including the editor of Bede's works, Charles Plummer, have seen in Bede's writings a dislike of Wilfrid. The historian Walter Goffart goes further, suggesting that Bede wrote his Historia as a reaction to Stephen's Vita Sancti Wilfrithi, and that Stephen's work was written as part of a propaganda campaign to defend a "Wilfridian" party in Northumbrian politics. Some historians, including James Fraser, find that a credible view, but others such as Nick Higham are less convinced of Bede's hostility to Wilfrid.