The action of the Sixth Ecumenical Council, affirmed by subsequent popes, was considered proof for centuries that popes were not infallible. Yet a strong-willed despot, Pope Pius IX , through threats and manipulation, would engineer an affirmation of papal infallibility by the First Vatican Council in 1870. Yet popes have almost made a business of contradicting one another on key issues. The later is shown as an antipope, but Agapetus , who sided with him, is shown as a true pope. Both men are shown as legitimate popes.
History conclusively denies both apostolic succession and papal infallibility .
To establish that dogma once for all, he convened the First Vatican Council December 8, 1869.