Final answer:
The term 'papal supremacy' was created in the 11th century when the Catholic Church solidified its power with the investiture controversy. Pope Gregory VII's ban on simony led to a rebellion against the Holy Roman Emperor and strengthened papal authority, making the popes the leaders of the western Church.
Step-by-step explanation:
The term “papal supremacy” was created in the 11th century. During this time, the Catholic Church solidified its power with the investiture controversy. Pope Gregory VII banned the practice of simony, where church officials were appointed by kings who took bribes. This led to a rebellion against the Holy Roman Emperor and the strengthening of papal authority. The popes gained power and became the leaders of the western Church.