Battering ram in the context of "Château des Baux"

A siege engine is a device that is designed to break or circumvent heavy castle doors, thick city walls and other fortifications in siege warfare. Some are immobile, constructed in place to attack enemy fortifications from a distance, while others have wheels to enable advancing up to the enemy fortification. There are many distinct types, such as siege towers that allow foot soldiers to scale walls and attack the defenders, battering rams that damage walls or gates, and large ranged weapons (such as ballistas, catapults/trebuchets and other similar constructions) that attack from a distance by launching heavy projectiles. Some complex siege engines were combinations of these types.

Siege engines are fairly large constructions – from the size of a small house to a large building. From antiquity up to the development of gunpowder, they were made largely of wood, using rope or leather to help bind them, possibly with a few pieces of metal at key stress points. They could launch simple projectiles using natural materials to build up force by tension, torsion, or, in the case of trebuchets, human power or counterweights coupled with mechanical advantage. With the development of gunpowder and improved metallurgy, bombards and later heavy artillery became the primary siege engines.

A siege tower or breaching tower (or in the Middle Ages, a belfry) is a specialized siege engine, constructed to protect assailants and ladders while approaching the defensive walls of a fortification. The tower was often rectangular with four wheels with its height roughly equal to that of the wall or sometimes higher to allow archers or crossbowmen to stand on top of the tower and shoot arrows or quarrels into the fortification. While the towers were primarily constructed of wood and thus flammable, their builders typically incorporated whatever non-flammable coverings could be readily procured including iron and/or fresh animal skins.

Evidence for use of siege towers in Ancient Egypt and Anatolia dates to the Bronze Age. They were used extensively in warfare of the ancient Near East after the Late Bronze Age collapse, and in Egypt by Kushites from Sudan who founded the 25th dynasty. During classical antiquity they were common among Hellenistic Greek armies of the 4th century BC and later Roman armies of Europe and the Mediterranean, while also seeing use in ancient China during the Warring States Period and Han dynasty. Siege towers were of unwieldy dimensions and, like trebuchets, were therefore mostly constructed on site of the siege. Taking considerable time to construct, siege towers were mainly built if the defense of the opposing fortification could not be overcome by ladder assault ("escalade"), by mining, or by breaking walls or gates with tools such as battering rams.

The siege of Gurganj occurred during the Mongol invasion of the Khwarazmian Empire. The siege's length is variable, with historians such as Rashid al-Din Hamadani stating that it lasted for seven months, but it is largely agreed that it ended with the defeat and annihilation of the city in April 1221. Genghis Khan, ruler of the Mongol Empire, had launched a multi-pronged assault on the Khwarazmian Empire, ruled by Shah Muhammad II. Through a combination of efficient planning and excellent manoeuvering, the Khan's army managed to take the border town of Otrar swiftly, followed by the large cities of Bukhara and Samarkand. The siege, among others, was witnessed by the Persian biographer Shihab al-Din Muhammad al-Nasawi, who recorded an account in Arabic c. 1241.

Genghis sent a detachment, led by his sons Jochi and Chagatai, northwest to lay siege to the former capital of Gurganj. Immensely wealthy, the city lay on marshy grounds on the delta of the Amu Darya, making it difficult to assault. Adapting to the lack of stones to use as projectiles, the Mongols cut down huge groves of mulberry trees, soaked the trunks in water to harden them, and used them as battering rams and catapult projectiles.

A casemate is a fortified gun emplacement or armoured structure from which guns are fired, in a fortification, warship, or armoured fighting vehicle.

When referring to antiquity, the term "casemate wall" means a double city wall with the space between the walls separated into chambers, which could be filled up to better withstand battering rams in case of siege (see § Antiquity: casemate wall.)

In warfare, ramming is a technique used in air, sea, and land combat. The term originated from the battering ram, a siege engine used to bring down fortifications by hitting it with the force of the ram's momentum, and ultimately from male sheep. Thus, in warfare, ramming refers to hitting a target by running oneself into the target.

Today, hand-held battering rams are one tool among many used by law enforcement and military personnel for door breaching. Forcible entry by criminals has been implemented using such methods as vehicles rammed into buildings.

The C1 Ariete (English: battering ram, ram) is a 3rd generation main battle tank of the Italian Army, developed by Consorzio Iveco Oto Melara (CIO), a consortium formed by Iveco and OTO Melara. The chassis and engine were produced by Iveco, while the turret and fire-control system were supplied by OTO Melara. The vehicle carries the latest optical and digital-imaging and fire-control systems, enabling it to fight day and night and to fire on the move. Six prototypes were developed by 1988, which were subject to intensive testing. The following year the vehicles travelled a combined 16,000 km. Deliveries were first planned for 1993, and took place in 1994 due to delays. Final delivery occurred 7 years later in August 2002.