Topic summary
Star fort

Extracted from the Wikipedia article Bastion fort.
Effectiveness
Two star forts were built by the Order of Saint John on the island of Malta in 1552, Fort Saint Elmo and Fort Saint Michael. Fort Saint Elmo played a critical role in the Ottoman siege of 1565 when it managed to hold out heavy bombardment for over a month. Eventually it fell, but the Ottoman casualties were very high, and it bought time for the relief force which arrived from Sicily to relieve the rest of the besieged island. The star fort therefore played a crucial and decisive role in the siege.