Papal Fortifications & the 1527 Sack – Bastions and Survival

Fortification was a long project: Boniface IX prepped for cannon age; Nicholas V layered crenellations, towers, and stores; Alexander VI added bastions, moat, and cells.

1. The Fortification Phases

• Boniface IX: foundations for artillery; prison use formalized.
• Nicholas V: crenellated curtain, three towers, logistics rooms for grain and oil—siege resilience.
• Alexander VI: fourth tower, bastions, moat, torture rooms; a hard edge to papal power.

2. 1527: Failure of Politics, Trial by Fire

Troops unpaid; discipline collapsed. Churches sacked, libraries looted, bodies unburied—disease followed. Clement VII survived via Passetto, but Rome’s population collapsed from ~55,000 to under 10,000.

3. Inside the Fortress During the Crisis

• Apartments served governance and refuge; the Stufetta offered modern comforts—jarring contrast to agony outside.
• Artillery platforms used; defensive choreography managed entry flows along ramp.

4. Aftermath & Memory

Trauma redirected papal policy and patronage; the fortress remained symbol of last-resort sovereignty.

Bottom Line

By 1527 the castle was more than walls—it was Rome’s nervous system under attack. The fortress held; the city changed forever.