-| ENG |-
La fortificazione alla moderna è un tipo di fortificazione elaborato a partire dal XV secolo per ovviare al problema posto dallo sviluppo dell'artiglieria. Fino ad allora l'efficacia delle fortificazioni era legata soprattutto alla loro altezza, l'azione difensiva denominata "difesa piombante", era costituita dal getto dall'alto di oggetti offendenti e liquidi bollenti, mentre l'assedio prevedeva la scalata o comunque il raggiungimento della sommità delle mura. L'artiglieria del XV secolo rivoluzionerà tale situazione portando gli architetti del tempo a concentrarsi sulla protezione delle cortine (tratti rettilinei fra torre e torre, o fra bastione e bastione) che erano il principale bersaglio delle artiglierie d'assedio. Per controbattere questa tattica si sperimentò il cosiddetto fuoco di rovescio: una struttura sporgente dalle cortine, appositamente irrobustita e provvista di postazioni d'artiglieria che potevano colpire le fanterie che cercassero di lanciarsi all'assalto della breccia creata nella cortina.
La Fortezza da Basso fu costruita nel 1534 - 1537 per ordine di Alessandro de' Medici da Pier Francesco da Viterbo e Antonio da Sangallo il Giovane. La Fortezza di San Giovanni Battista (dal nome del santo patrono della città) è a forma pentagonale, dove la figura umana risulta perfettamente inscritta nel perimetro, fu realizzata in breve tempo e con grandezza di mezzi, voleva essere sia di monito ai Fiorentini, con la sua massa ricca di possenti bastioni, torrette e camminamenti, sia assicurare rifugio ai governanti in caso di rivolta. Durante il periodo di Firenze capitale d'Italia i fossati furono livellati e le muraglie interrate.
Come gran parte di queste strutture non venne mai utilizzata e rimase del demanio Militare fino al 1967.
Ora la Fortezza da Basso ospita le più importanti manifestazioni di Firenze Expo ed è sede di numerosi convegni, meeting, concerti ed iniziative nazionali ed internazionali.
-| ITA |-
A Star Fort, or trace italienne, is a fortification in the style that evolved during the age of gunpowder, when cannon came to dominate the battlefield, and was first seen in the mid-15th century in Italy. Passive ring-shaped (enceinte) fortifications of the Medieval era proved vulnerable to damage or destruction by cannon fire, when it could be directed from outside against a perpendicular masonry wall. The star fortress was a very flat structure composed of many triangular bastions, specifically designed to cover each other, and a ditch. In order to counteract the cannon balls, defensive walls were made lower and thicker. Although this made their climbing easier, the ditch was widened, so that attacking infantry was still exposed to fire from a higher elevation for a while, including enfilading fire from the bastions. The outer side of the ditch was usually provided with a glacis to deflect cannon balls aimed at the lower part of the main wall. When the newly effective maneuverable siege cannon came into military strategy in the fifteenth century, the response from military engineers was to arrange for the walls to be embedded into ditches fronted by earthen slopes so that they could not be attacked by destructive direct fire and to have the walls topped by earthen banks that absorbed and largely dissipated the energy of plunging fire. The key to the fort's defence moved to the outer edge of the ditch surrounding the fort, known as the covered way, or covert way. Defenders could move relatively safely in the cover of the ditch and could engage in active countermeasures to keep control of the glacis, the open slope that lay outside the ditch, by creating defensive earthworks to deny the enemy access to the glacis and thus to firing points that could bear directly on to the walls and by digging counter mines to intercept and disrupt attempts to mine the fort walls.
The Fortress “Da Basso” was built from 1534 - 1537 on the orders of Alessandro de' Medici, by Pier Francesco da Viterbo and Antonio da Sangallo the Younger. The pentagonal-shaped, where the human figure perfectly results subscribed in the perimeter, Fortezza di San Giovanni Battista (Fortress of St John the Baptist – it takes its name from the patron saint of the city) was built in a short space of time and using great means. It was meant to be both a warning to the Florentines, with its bulk filled with mighty ramparts, turrets and patrol ways, and also to assure the governors of a refuge in case of revolt. During the period in which Florence was capital of Italy, the moats were filled in and the walls buried.
A large part of these structures was never used and it remained military property until 1967.
Now the Fortress “Da Basso” houses the most important exhibitions of Florence Expo and is the location of numerous conventions, meetings, concerts and national and international events
