Bastion fortification in Verona
The Italian architect Michele Sanmicheli (1484-1559) began in 1527 to rebuild the fortifications of Verona to a new system of angled bastions. A mediaeval round or square tower stood on its own and could not defend the stretch of wall between itself and the next tower: an attacker at the foot of the wall stood in a dead zone. A pentagonal bastion projecting from the wall gave crossfire from the neighbouring bastions; no dead zones remained.
The geometry, the 'trace italienne', spread across Italy, the Low Countries and Germany by the mid-sixteenth century and by the seventeenth had become the European standard. The immediate technical reason why sixteenth-century citadels stopped holding out under medieval siege, and why siege itself turned into a predictable engineering problem.
Why this date
exact: 1911 Britannica dates the start of Sanmicheli's work on Verona's bastions to 1527.
Node sources
- Encyclopædia Britannica, 11- (1911), «Sanmichele, Michele», Wikisource Verified 28 Sep 2026
In 1527 Sanmichele began to transform the fortifications of Verona according to the newer system of corner bastions, a system for the advancement of which he did much valuable service.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.