Final answer:
Pope Leo X was the Medici pope who was in power when Martin Luther posted the 95 Theses in 1517, marking the start of the Protestant Reformation.
Step-by-step explanation:
The Medici pope who was in power when Martin Luther posted the 95 Theses in 1517 was Pope Leo X. He belonged to the powerful and wealthy Medici family, who influenced the Catholic Church and European art significantly.
Pope Leo X's patronage of art included commissioning works from Raphael and was a sign of the cultural significance of the Medici family. Under his papacy, the church witnessed important historical events, including the beginning of the Protestant Reformation.
The Medici pope who was in power when Martin Luther posted the 95 Theses in 1517 was Pope Leo X. He was born into the influential and wealthy Medici family and was appointed as an abbot at the age of 7 and a cardinal at the age of 13, due to his family's influence.
Pope Leo X is known for his patronage of artists such as Raphael and for commissioning works that contributed to the flourishing of the arts during the Renaissance.