Reactionary pope best known for his unprecedented liberal reforms and the length of his papacy: 32 years! Endorsement on the reverse of a one page undated letter to Pius IX from the future Bishop of Rieti requesting that he be consecrated on the second Sunday of January by Cardinal Filippo Maria Guida. Endorsed on the reverse in black ink, '11, Jan. 72...Pius I.' In fine condition. RRAuction COA.