The abbess's authority reached its furthest extent in the double monasteries of the early medieval period, communities of both monks and nuns governed by a single abbess, the most celebrated example being Hilda of Whitby, who ruled such a house in seventh century Northumbria and hosted the Synod of Whitby in 664, a gathering that settled the date of Easter for the English church under her roof.
Some medieval abbesses held authority extending well beyond spiritual government of their own community. The abbess of Las Huelgas in Spain exercised a quasi-episcopal jurisdiction over the clergy and parishes attached to her abbey for centuries, confirming appointments and hearing cases in a manner otherwise reserved to a bishop, an extent of authority that later ecclesiastical reform curtailed. A small number of English abbesses, as tenants-in-chief of the crown, were summoned to parliament in the medieval period, though without a vote.
Vocations to the office have fallen in Western Europe and North America since the 1960s in step with the broader decline in women's religious life, while communities in Africa and Asia have grown, and double monasteries of the early medieval type have not survived into the modern church in any of the traditions that once had them.