The Rt Rev Rachel Treweek swore an oath to Parliament and her allegiance to the Queen to become the first female with enough Church seniority to be appointed Westminster's 'Bishops Bench'.
Walking across the Lords chamber, Treweek went to shake the hand of Speaker and Crossbench convener Baroness D'Souza. The clasp prompted enthusiastic clapping from members, in scenes described by some pundits as "unseen before".
Speaking, Treweek announced: "I Rachel, Lord Bishop of Gloucester, do swear by Almighty God that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth, her heirs and successors, according to law. So help me God."