The movement was formalised on 9 June 1990 at St Alban's Church Holborn in London by a number of Anglo-Catholic clergy in the Diocese of London who had been marginalised within, or expelled from, existing Anglo-Catholic groups because of their support for women's ordination to the priesthood. It developed a theological stance which was staunchly liberal in matters of inclusivity but traditionally Catholic in matters of liturgy and the centrality and theology of the sacraments whilst believing that traditional restrictions on who may receive them should be re-examined.
Prominent supporters include the Archbishop of Canterbury, the Most Reverend and Right Honourable Rowan Williams, as well as the openly gay Dean of St Albans, the Very Reverend Jeffrey John, both of whom have served on the executive committee of British / Irish Affirming Catholicism in recent years. In North America, bishops involved in AAC include Frank Griswold, former presiding bishop of the Episcopal Church USA, and Archbishop Andrew Hutchison, former Primate of the Anglican Church of Canada. AAC has ties with the Society of Catholic Priests.