Such projectiles would almost demolish a house, and were nearly as formidable as modern shells; their great weight would batter every portion of a medieval castle except the very thickest of walls. The platforms of earth thrown up by besiegers to sustain their great engines remain in many places intact to-day; thus round Berkhampstead Castle are eight, upon which the trebuchets of the Dauphin were erected in 1216, when he battered the castle into submission in about a fortnight. The terms mangonel, petrary, balista, onager, scorpion, perrier, catapult, etc., when used by historians of the middle ages, generally apply to the trebuchet and its varieties, large and small.
The Arblast, Espringale, and Spurgardon were engines based upon the cross-bow or tension principle; some were of considerable size and threw huge bolts tipped with iron. Another and a common use was to convey ignited incendiary matter into the enemy's quarters by their means. They were mounted upon towers, curtain walls, and in the baileys, while in the open when placed upon wheels they served the purpose of field-pieces.
RAISING THE PORTCULLIS.
The Ram, based upon the weapon used by the ancients, was in frequent use. The working parts and the men manipulating it were protected by a pent-house called the "Snail," or "Whelk," having a roof of considerable thickness. In this house it was suspended by chains and pulled backwards and forwards by hand or mechanical appliances; when released, it smashed the stones in the wall to powder, so that they could be subsequently removed from the defences. To mitigate the effects the besieged let down mattresses, bags of wool, and coiled rope mats by chains from the ramparts.
The Terebra.—A machine based upon the classical terebra was also in use. It consisted of a heavy beam which could be rotated; the iron head being furnished with a spike of square section was inserted in a joint into which it bored its way, breaking up the surrounding stones and facilitating their removal.
The Cat, or Sow, was in constant use for mining and underpinning walls. It was a covered house upon wheels, with an enormously strong roof calculated to withstand the heavy stones, beams of wood, hot water, molten lead, and spiked poles which were invariably launched from the battlements for its destruction. Under its cover the besiegers tunnelled beneath the walls, which they supported with woodwork until their task was completed; by starting a conflagration in the chamber thus excavated the supports were consumed and the wall was breached. At other times the stones, previously shattered or loosened by the ram or the terebra, were removed until the wall above was incapable of bearing its own weight. Mining, like other operations, had to be carried out with discretion and was undoubtedly a precarious operation. Thus in the siege of Dryslwyn Castle, Carmarthenshire, in the time of Edward I., Lord Stafford and other leaders lost their lives by a sudden collapse of the walls they were undermining. The mine was often met by a counter-mine of the garrison as in modern warfare.
The Beffroi, Belfry, or Movable Tower was a machine for facilitating the capture of fortified positions. It could be built upon the spot or carried from place to place in pieces. When mounted upon wheels it was pushed forward towards the walls, the object being to give the assailants the same advantage of height which was shared by the besieged. From the upper platform the archers could command the battlements and approaches; those in lower stages sent their missiles into loopholes and other openings; in the lowest stage a ram was often mounted. One feature of its construction was a hinged platform which fell outwards upon the battlements and over which the assailants endeavoured to enter the fortress. The besieged hindered the approach of this terror by digging pitfalls for the wheels, shooting incendiary missiles, making sallies for its destruction by fire, or concentrating such a body of men upon the walls that none could live under the hail of missiles poured into it.
The methods of assailing a castle thus enumerated were, as a rule, put into operation at the same time and supported one another. Thus in the siege of Bedford Castle, defended by the followers of Faukes de Breauté, in 1224, the siege was carried out by King Henry III. in person. Two wooden Beffrois were made and advanced towards the walls,—these were occupied by longbow-men and arbalestiers; sappers approached the walls and undermined by means of a Cat; seven trebuchets cast their ponderous projectiles against, or into, the castle without intermission night and day, while lesser artillery hurled lead-covered stones, darts, bolts, and other missiles among the defenders upon the walls, or through the oillets and louvre-covered windows. The barbican was taken and then the outer bailey; a breach in the defending wall gave admission to the inner bailey, and when, by judicious sapping, one portion of the great Shell Keep sank and produced a wide breach, the castle was surrendered.