Final answer:
Pope Gregory VII developed the way bishops were chosen and excommunicated King Henry IV, reinforcing the Church's authority over secular rulers.
Step-by-step explanation:
The pope who developed the way bishops were chosen and stood up to King Henry IV by having him excommunicated was Pope Gregory VII. His actions during the investiture controversy in 1075 greatly impacted the power dynamics between the church and the state. Pope Gregory VII's bold move to ban simony and excommunicate Henry IV reinforced the papacy's authority over secular rulers and initiated the practice wherein bishops were to be elected by the clergy rather than appointed by kings. These changes marked a significant shift in the relationship between the Church and European rulers.