In volume II.
a brief account is given of the 'Malines Conversations' between Cardinal Mercier and an unofficial delegation of Anglican clergymen, 1921-25, also Leo XIII.'s encyclical on Anglican orders and Pius XI.'s encyclical, 1928, setting forth the Vatican's attitude to the movement toward Church unity brought to its attention by the Appeal of the Lambeth Conference, 1920, a copy of which was sent to Rome, and by the invitation to take part in the Lausanne Convention. Pius demanded unconditional submission to the Roman see from all Protestants, including Anglicans.