St. Nicholas I the Great

Nicholas · 858 – 867

Asserted papal supremacy over kings and patriarchs alike, defending a queen's rights and challenging Constantinople.

Nicholas I became pope in 858 and immediately began exercising authority with a force not seen since Leo the Great. When King Lothair II of Lotharingia tried to annul his marriage to take a new wife, Nicholas overruled two archbishops who had approved the divorce and ordered Lothair to take his queen back. It was a stunning assertion of papal authority over royal marriages. He also clashed with Patriarch Photius of Constantinople over jurisdictional claims in Bulgaria, deepening the rift between East and West. Nicholas insisted that papal decrees had the force of canon law and that no council or bishop could override the pope. His position was aggressive, but it established precedents that shaped the medieval papacy.

Standing Up to a King

When Nicholas told Lothair his divorce was invalid, he was defying a powerful king and two compliant archbishops. He deposed the archbishops and held firm. It was one of the clearest early demonstrations that the pope would defend the sacrament of marriage against political pressure, a principle the Church still upholds.