Julius expected that the pendentive above the altar would show Saint Peter, his right hand pointing skyward and his left holding the keys Jesus gave him: the keys to the Kingdom of Heaven.
It made sense: Who else but the first pope could possibly sit above the altar in the chapel where his successors would be named?
Furthermore, Peter was personally significant to Julius, for the pope sat on the throne of Saint Peter, which made Julius the living descendant of the apostles.
It was the biggest obstacle Michelangelo needed to address in making the case for prophets instead of apostles. He needed to find a prophet worthy of displacing Saint Peter.
He sketched the 16 prophets who had books in the Old Testament. He thought about their lives and their stories. He sketched more.
In the end, he settled on Isaiah as the strongest choice. Isaiah preached against arrogance and hypocrisy, appealed for justice, and spoke of the promise of salvation. Isaiah also offered the prophesy of a Messiah to come:
The virgin will conceive and give birth to a son, and name him Immanuel…and he will be called Wonderful, Counselor, Mighty God, Everlasting Father, Prince of Peace.
Michelangelo thought he might be able to convince Julius that the ceiling was about the Old Testament, not the New, particularly since the life of Christ was already told on the wall frescoes below. In that case, who better to sit above the altar than Isaiah in the moment he foretells the coming of Christ?
Every time Michelangelo stood in the chapel trying to imagine Isaiah sitting on the throne above the altar, his heart sank again. It was going to be difficult to push Saint Peter off that throne.
He was even beginning to wonder if it was worth the fight, until Bramante and Raphael offered their opinions.
Next: Prophets and Sibyls (3)