Editing Siege (section)

====Industrial advances====
{{Unreferenced section|date=September 2022}}
[[File:Detaille - Engineer Corps, Siege of Anvers, 1832.jpg|thumb|right|French Engineer Corps during the [[Siege of Antwerp (1832)|siege of Antwerp]], 1832]]

Advances in artillery made previously impregnable defenses useless. For example, the walls of [[Battle of Vienna|Vienna]] that had held off the [[Ottoman Empire|Turks]] in the mid-17th century were no obstacle to [[Napoleon]] in the early 19th.

Where sieges occurred (such as the [[siege of Delhi]] and the [[siege of Cawnpore]] during the [[Indian Rebellion of 1857]]), the attackers were usually able to defeat the defenses within a matter of days or weeks, rather than weeks or months as previously. The great Swedish white-elephant fortress of [[Karlsborg Fortress|Karlsborg]] was built in the tradition of Vauban and intended as a reserve capital for Sweden, but it was obsolete before it was completed in 1869.

Railways, when they were introduced, made possible the movement and supply of larger armies than those that fought in the Napoleonic Wars. It also reintroduced siege warfare, as armies seeking to use railway lines in enemy territory were forced to capture fortresses which blocked these lines.

During the [[Franco-Prussian War]], the battlefield front lines moved rapidly through France. However, the Prussian and other German armies were delayed for months at the [[Siege of Metz (1870)|siege of Metz]] and the [[Siege of Paris (1870–1871)|siege of Paris]], due to the greatly increased firepower of the defending infantry, and the principle of detached or semi-detached forts with heavy-caliber [[artillery]]. This resulted in the later construction of fortress works across Europe, such as the massive fortifications at [[Verdun-sur-Meuse|Verdun]]. It also led to the introduction of tactics which sought to induce surrender by bombarding the civilian population within a fortress, rather than the defending works themselves.

The [[Siege of Sevastopol (1854–1855)|siege of Sevastopol]] during the [[Crimean War]] and the [[siege of Petersburg]] (1864–1865) during the [[American Civil War]] showed that modern citadels, when improved by improvised defences, could still resist an enemy for many months. The [[siege of Plevna]] during the [[Russo-Turkish War (1877–1878)]] proved that hastily constructed field defenses could resist attacks prepared without proper resources, and were a portent of the trench warfare of World War I.

Advances in firearms technology without the necessary advances in battlefield communications gradually led to the defense again gaining the ascendancy. An example of siege during this time, prolonged during 337 days due to the isolation of the surrounded troops, was the [[siege of Baler]], in which a reduced group of Spanish soldiers was besieged in a small church by the [[Philippines|Philippine]] rebels in the course of the [[Philippine Revolution]] and the [[Spanish–American War]], until months after the [[Treaty of Paris (1898)|Treaty of Paris]], the end of the conflict.

Furthermore, the development of [[steamship]]s availed greater speed to [[blockade runner]]s, ships with the purpose of bringing cargo, e.g. food, to cities under blockade, as with [[Charleston, South Carolina]], during the American Civil War.