Final answer:
The tradition of Caesaro-Papism is typically associated with Byzantine emperors, with Emperor Constantine the Great being a notable figure in its early form. Popes like Gregory the Great played significant roles in establishing papal authority and independence from Caesaro-Papism, using relationships with rulers and the doctrine of Petrine Succession to assert this authority.
Step-by-step explanation:
The tradition of Caesaro-Papism, which denotes a political-theological system wherein the head of the state is also the head of the church, does not have a singular 'founder' as it was more a product of historical evolution rather than an invention by an individual.
However, an early form of this system can be seen under the leadership of Byzantine emperors, with Emperor Constantine the Great often associated with this tradition as he played a significant role in the Christianization of the Roman Empire and brought the Church under the influence of the state.
Later, this model was challenged and transformed as the papacy sought greater independence and authority over Christian affairs.
Popes played a pivotal role in shaping the Christian church's hierarchy and authority. As we see with figures like Gregory the Great, the papacy established its independence and ecclesiastical power, despite not founding Caesaro-Papism itself.
Gregory was adept in asserting papal authority during his papacy at the turn of the seventh century by fostering relationships with rulers, promoting missionary work, and leveraging the Petrine Succession which is a doctrinal assertion of papal primacy based on the apostle Peter.
This set a precedent for later claims of papal supremacy over both spiritual and temporal powers, often in opposition to the Caesaro-Papist notion. Meanwhile, documents such as the forged Donation of Constantine were used to bolster these claims, although the popes' actual power was frequently contested and limited by political circumstances.