Artillery Fortifications: angle bastions
The overhaul of historic castles or town walls to meet the challenge of gunpowder weapons tended to be piecemeal because of the enormous costs involved. Following the French king Charles VIII's destruction of Italian strongholds in 1497, engineers developed a system of broad and low ramparts that were defended by mutually supporting angel bastions known as the Italian Trace and these required drastic re-organisation on a scale not previously seen. Berwick upon Tweed on the Anglo-Scottish border is a good example of how Tudor monarchs responded to the new warfare, albeit in a piecemeal fashion. Henry VIII added earth and timber ‘bulwarks’ at points around the medieval wall circuit and a stone gun tower at the north-east corner (the ‘Lord’s Mount’). Edward VI’s reign saw construction of a square Italianate fort with pointed corner bastions across the seaward front of the town wall. Defences built to the 1558 design of Elizabeth I’s engineer Sir Richard Lee abandoned part of the medieval town and laid out new walls on a vast scale with large angular bastions at intervals around the circuit of broad earthen ramparts faced with stone.
The medieval town of Berwick was defended by a castle (A) at the north-west corner of the town walls (A-B-C) overlooking the river Tweed. King Henry VIII upgraded this circuit in 1522-3 with the addition of five timber and earthwork gun batteries, or bulwarks, placed immediately outside the town ditch. A stronger addition at the north-east corner was the massive Lord’s Mount gun tower (B) started in 1539. The medieval circuit was further strengthened in 1550 by the Citadel, a square earthwork fort with pointed corner bastions. Remains of the outermost two bastions (E) and of the Bulwark of the Snook (D) still survive on the side facing the North Sea front. This arrangement was completely replaced on the north and east sides of the town by Lee’s Italianate bastioned curtain (F), which left the castle and northern part of Berwick town outside the new walls (Photographed 1990).
While Berwick was still enclosed by its medieval walls, several miles to the north this headland guarding Eyemouth Bay, Berwickshire was fortified by Sir Richard Lee in 1547.
Lee's fort employed a central pointed bastion, with two sets of double gun emplacements angled to cover the bastion faces and the short curtain walls on either side. This is the earliest surviving example of an Italian trace in the British Isles.
In 1557 a larger area of the headland was fortified by a French engineer, possibly Jean Roytell, with a single curtain with two demi-bastions on each flank. Lee’s fort had been dismantled by treaty, but the earthworks remained and may have been re-used as a second line of defence by the French (photographed 1991).
The principles evolved by Italian engineers can be seen throughout the globe, as a result of colonisation by European powers.
Plan of the Venetian fortifications of Corfu, facade of Santa Maria del Giglio, Venice, carved by Guiseppi Sardi, 1678-1683. The Old Citadel to the left is still separated from the town by a sea moat and massive curtain with bastions at both ends (photographed 2016).
Defences of the Venetian Old Citadel of Corfu today, looking north from the bridge depicted in the carving of Sardi (photographed 2016).
A southern prospect of the bastioned city of Lucca from the Altar of Liberty in Lucca Cathedral, carved by Flemish sculptor Giambologna (Jean de Boulogne) in 1577-9. At this stage in its development only some of the round gun platforms had been replaced by angle bastions with protected flankers (photographed 2015).
The walls of Lucca, Tuscany. The San Regolo Bastion with its curving flanks (‘orillons’ or ‘ears’ to protect its recessed gun batteries), as seen over the equivalent battery, or ‘flanker’ in the Libertà Bastion. Both bastions were added to the town walls in this form in the 1620s and their oblique faces were designed to leave no shelter to an attacking force, covered as they were by the guns of their neighbour (photographed 2015).
The Forte de Santa Luzia, Elvas, Portugal as seen from the town walls. In the foreground is the glacis, ground artificially sloped beyond the walls and dry ditch that has been cleared of anything that might give cover to an attacking force. Similar treatment has been given to the fort, the deceptively low profile of which conceals a wide and deep dry ditch in front of the main wall (photographed 1976).
18th century plan of Cochin fort on India's Malabar coast of India. Little of the walls now exists, but the plan shows how defence in depth was an essential feature of artillery fortifications (photographed 2019).