Siege

From Old French sege, siege; modern siége, seat: from sedere, to sit. The 'sitting down' of an army or military force before a fortified place for the purpose of taking it either by direct military operations or by starving it into submission.

The science of siege warfare reached its most complicated development in the 17th and 18th centuries. Fortresses were first blockaded, so as to cut off all intercourse from without, the besieging force encamping just beyond the reach of the enemy's guns. Detached works, if any, had to be captured before the opening of the trenches began. There were laid out in zigzag form, the prolongation's of which were directed so as to clear the works of the fronts attacked; and when a direct advance became necessary they were provided with traverses at short intervals, or blind saps were used, i.e. trenches covered in with timber and earth. These, when two or three of such lines of approach were used, were termed parallels, and it was by the aid of these parallels that the batteries, dispersed over a wide area, concentrated their fire upon the revetments. Not only were those parallels formed to approach the walls of the fortress, but the resources in men and ammunition were, by the nature of the case, largely in favour of the besiegers, who were constantly harassed by the artillery of the besieged. Therefore a line of circumvallation or a covering field army was employed. The former mode of protection provided for the surrounding of the place attacked with a high bank of earth, while the latter, by virtue of its greater mobility, was able to meet the relieving army many kilometres from the line of action.

This mode of warfare gave rise to an immense technical literature from the reign of Louis XIV to the end of the 18th century, probably because the warfare of position was suited to the politics of alternating aggression and diplomacy, and also to the tactics of small, professional, non-national armies of the 17th and 18th centuries. The possession of this or that fortress could be used as a counter for diplomatic bargains, and its capture or denial to the enemy was a more satisfying objective for a mercenary general than the destruction of the enemy main force, which might mean an untimely end to the war, the disbanding of the victors, and the unemployment of their commander. Hence the need for an elaborate technique whose fine points would not be intelligible to the monarch or minister who employed such commanders.

When a more realistic and ruthless mode of warfare was adopted by the armies of the French revolutionary period, siege warfare receded to a position of lesser importance, and as the 19th century progressed the power of artillery to destroy rapidly outstripped the skill of military engineers to protect fortresses. Though money and labour were still lavishly expended on fortifications, only two protracted sieges of military importance occurred in that century - at Sevastopol and Paris. On the outbreak of war in 1914 the forts of the French and Belgian frontiers proved as ineffective as in 1870, and when the defensive finally asserted itself over the offensive war in western Europe was stabilised about a system not of fortresses, but of field works.

In the Second World War, while it was demonstrated that under modern conditions no purely military fortress could stand a siege of any length, a large fortified town could do so, and though it could not continue to function as a town could yet maintain a kind of life devoted to purely military ends. Tobruk was twice besieged and so were all the Atlantic and many of the Channel ports of France. Stalingrad was the scene of two successive sieges, first of the Soviet garrison by the Germans and then vice versa. Leningrad sustained the longest siege, and was also the most expensive.

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