An illuminating episode in the religious life of the Magonsætan is known because it came to the attention of Boniface and his correspondent Eadburg, who may have been a nun at Wimborne in Wessex. The letter of Wynfrith (Boniface) to Eadburg describing the vision of a brother at Wenlock must have been written before the spring of 719, when he changed his name to Boniface on the occasion of his visit to Rome, but after the death of Ceolred, king of Mercia, in 716, for Boniface remarks that Ceolred was ‘without doubt still alive’ when the visionary saw him in hell. The latter phrase suggests that the vision itself fell in 715 or 716.

Eadburg had asked Boniface to send her a written account of the wonderful visions of the man ‘in Abbess Mildburg's monastery who recently died and came to life again’ just as he had learnt them from the venerable Abbess Hildelith. This Hildelith, abbess of Barking, was a person of considerable literary attainments, as we can see from the dedication of Aldhelm's prose De uirginitate and from Bede's extracts from a then widely known libellus, largely concerned with visions, compiled at her East Saxon monastery. The extent to which the account Boniface eventually sent to Eadburg was indebted to any oral or written report from Hildelith is unclear, however, for he states that he recounts the vision as he himself, with three witnesses, heard it from the visionary's own lips ‘while he [the visionary, or if peruenit is emended to perueni, Boniface] recently came to those regions from overseas’.