Which pope appointed Michelangelo as chief architect of St. Peter's Basilica?

Which pope appointed Michelangelo as chief architect of St. Peter’s Basilica? Pope Paul III appointed him.

In 1546, Pope Paul III placed Michelangelo in charge of the architectural work at St. Peter’s Basilica after the death of Antonio da Sangallo the Younger. Michelangelo was already in his seventies, but Paul III trusted his artistic judgment and gave him authority over the project’s direction.

Michelangelo revised the basilica’s central design, simplifying the competing plans left by earlier architects, including Bramante and Sangallo. He strengthened the concept of a centralized Greek-cross plan and designed the imposing double-shell dome, although he died in 1564 before the dome was completed. Giacomo della Porta and Domenico Fontana later finished it, broadly following Michelangelo’s design.

The other papal names are connected with different stages of Michelangelo’s career. Julius II commissioned major projects such as the Sistine Chapel ceiling, while Leo X and Clement VII sponsored other works. Paul III, whose family name was Farnese, is the pope specifically associated with appointing Michelangelo to lead St. Peter’s architecture.