Valencia in 1811-12 sustained a siege of two months

Ciudad Rodrigo in 1812 sustained a blockade of several months, and a close siege of two weeks.

Badajos in 1812 sustained twenty-one days of open trenches.

Burgos in 1812 sustained thirty-three days of open trenches.

St. Sebastian in 1813 sustained a siege and blockade of nearly three months, with fifty-nine days of open trenches.

Pampeluna in 1813 sustained a siege of more than four months.

Monzon in 1813-14 also sustained a siege of more than four months.

This list might be increased with numerous other examples, to show that even poorly fortified towns are capable of defending themselves, on an average, for more than a month.  These examples, be it remembered, are nearly all taken from a period of history since any material improvements have been made in the art of attack.  Since the time of Vauban the improvements in attack have not kept pace with the increased means of defence.  Moreover, these examples are taken from the sieges of towns defended mainly by old and antiquated works, and entirely incapable of offering the same resistance as detached fortifications, with all the modern improvements.

The value of fortifications, as land defences, is sufficiently proved by showing their general capability of resisting an invader, even for a limited period; thus affording us time and opportunity to provide other means of security.  But it must not be inferred that forts besieged en regle will necessarily fall after so many days.  Such is far from being the case.  The besieged have usually great advantages over the besiegers; and unless the latter are vastly superior in number, or the work is of a very inferior character, or the garrison is destitute of the requisite means and energy to resist an attack, they will not be taken.

Mezieres was not taken in 1520; nor Marseilles in 1524; nor Peronne in 1536; nor Landrecies in 1543; nor Metz in 1552; nor Montauban in 1621; nor Lerida in 1647; nor Maestricht in 1676; nor Vienna in 1529, and again in 1683; nor Turin in 1706; nor Conde in 1744; nor Lille in 1792; nor Landau in 1793; nor Ulm in 1800; nor Saragossa in 1808; nor Burgos in 1812.  This list might be extended almost indefinitely with the names of places that could be reduced neither by force nor by starvation.

But, as has already been noticed, some have asserted that fortifications have become of little comparative importance, under the new system of warfare introduced during the wars of the French Revolution.  On this subject let us consult the opinions of the best military judges of the present century.

Napoleon says of fortifications, “they are an excellent means of retarding, fettering, enfeebling, and disquieting a conquering foe.”