Sarah Mullally, a one-time cancer nurse who became a priest, was installed as archbishop of Canterbury. She's publicly celebrating her election as the first woman ever to lead the Church of England. While the 63-year-old Mullally formally became the archbishop of Canterbury back in January, Wednesday’s event marks the beginning of her public ministry as both the head of the Church of England and spiritual leader of the worldwide Anglican Communion. The communion is an association of independent churches, including the Episcopal Church in the U.S., that together have more than 100 million members.