The story
- New Latin · derived fromcaesaro-papia
- English todaycaesaropapism
From caesar + -o- + papism, probably modelled after New Latin caesaro-papia, coined by the German ecclesiastical jurist Justus Henning Böhmer (1674–1749) in his work Jus ecclesiasticum Protestantium (Ecclesiastical Law of the Protestants, 1714–1736).
Etymology from Wiktionary, CC BY-SA 4.0.