The Old English text by Æthelwold, bishop of Winchester, known as ‘King Edgar's Establishment of Monasteries’ (EEM) is here viewed as an expression of royal ideology. The article argues that the final section of EEM, in the first person, should be interpreted as words attributed to Edgar himself. This re-reading strengthens the case for dating EEM to the period 966 x c. 970, and for suspecting a female audience. It is argued that EEM accompanied an early, feminized version of Æthelwold's translation of the Rule of St Benedict. This model of religious life related to the responsibility of Edgar's queen, Ælfthryth, for female houses, and reflected her alliance with Æthelwold. EEM offered a distinctive view of English ecclesiastical history subtly tailored to these purposes. The final section of EEM presented a sophisticated defence of female monastic endowment. Ælfthryth's role provides an important context for understanding the politics and representation of Æthelred's kingship in the 990s.