St Peter's Basilica Construction

Timeline

1. 1551–1555Vatican Hill · RomeAfter succeeding as chief architect in 1547, Michelangelo in the early 1550s concentrated on adjusting Bramante's Greek-cross plan, reinforcing the drum and buttresses to prepare the structural foundation for the colossal dome.
2. 1555–1559Vatican Hill · RomePope Paul IV ordered the nave shortened and the facade orientation adjusted, sparking a design dispute with Michelangelo; under papal financial and political pressure the project nonetheless maintained continuous construction of the stone main structure and buttress system.
3. 1557–1560Vatican Hill · RomeBy around 1560 the drum and the inner and outer double buttress system were largely formed, with masonry techniques supporting the subsequent closing of the dome, marking a key advance in the structural phase of Renaissance monumental religious architecture.