Sarah Mullally was officially confirmed on Wednesday as the first woman to lead the Church of England as Archbishop of Canterbury at a traditional ceremony at St Paul’s Cathedral in London.

The vast cathedral was converted into a court of law for the ancient Confirmation of Election, a legal ceremony set within a church service marking the moment an archbishop-elect legally assumes office.

Mullally, who will also serve as the spiritual head of 85 million Christians across 165 countries in the global Anglican Communion, took an oath of allegiance as the 106th Archbishop of Canterbury before senior bishops acting as Royal Commissioners under the authority of King Charles.

The British monarch has served as the Supreme Governor of the Church of England since Henry VIII split from the Roman Catholic Church in the 16th century.

The service showcased the breadth of the Church, bringing together bishops and clergy alongside local schoolchildren and choirs, with participants from across the Church of England and the Anglican Communion.

The wording of the confirmation has changed over the centuries, moving from Latin to English in the 18th century while retaining its roots in medieval canon law.

The service included hymns and readings reflecting the diversity of the global Anglican Communion, with music ranging from an anthem by English composer Edward Elgar to a South African Xhosa chant, as well as a bilingual reading in English and Portuguese.

Once England’s Chief Nursing Officer, Mullally was first named in October to replace Justin Welby as the Church’s most senior bishop. Her appointment drew immediate criticism from some conservatives in the global network of Anglicans who oppose women’s ordination and remain divided over LGBTQ+ relationships.

The 63-year-old, who also faces questions at home over past safeguarding failures in the Church, will be enthroned at Canterbury Cathedral in March when she will also preach her first sermon as Archbishop, marking the start of her public ministry.