Ignaz von Döllinger

Johann Joseph Ignaz von Döllinger (; 28 February 179914 January 1890), also Doellinger in English, was a German theologian, Catholic priest and church historian who rejected the dogma of papal infallibility. Among his writings which proved controversial, his criticism of the papacy antagonized ultramontanes, yet his reverence for tradition annoyed the liberals.

He is considered an important contributor to the doctrine, growth and development of the Old Catholic Church, though he himself never joined that denomination. Provided by Wikipedia