Fire lance in the context of "Jin-Song Wars"

Gunpowder is the first explosive to have been created in the world. Popularly listed as one of the "Four Great Inventions" of China, it was invented during the late Tang dynasty (9th century) while the earliest recorded chemical formula for gunpowder dates to the Song dynasty (11th century). Knowledge of gunpowder spread rapidly throughout Eurasia, possibly as a result of the Mongol conquests during the 13th century, with written formulas for it appearing in the Middle East between 1240 and 1280 in a treatise by Hasan al-Rammah, and in Europe by 1267 in the Opus Majus by Roger Bacon. It was employed in warfare to some effect from at least the 10th century in weapons such as fire arrows, bombs, and the fire lance before the appearance of the gun in the 13th century. While the fire lance was eventually supplanted by the gun, other gunpowder weapons such as rockets and fire arrows continued to see use in China, Korea, India, and this eventually led to its use in the Middle East, Europe, and Africa. Bombs too never ceased to develop and continued to progress into the modern day as grenades, mines, and other explosive implements. Gunpowder has also been used for non-military purposes such as fireworks for entertainment, or in explosives for mining and tunneling.

The evolution of guns led to the development of large artillery pieces, popularly known as bombards, during the 15th century, pioneered by states such as the Duchy of Burgundy. Firearms came to dominate early modern warfare in Europe by the 17th century. The gradual improvement of cannons firing heavier rounds for a greater impact against fortifications led to the invention of the star fort and the bastion in the Western world, where traditional city walls and castles were no longer suitable for defense. The use of gunpowder technology also spread throughout the Islamic world and to India, Korea, and Japan. The so-called Gunpowder Empires of the early modern period consisted of the Mughal Empire, Safavid Empire, and Ottoman Empire.

A firearm is any type of gun that shoots projectiles using high explosive pressure generated from combustion (deflagration) of chemical propellant, most often black powder in antique firearms and smokeless powder in modern firearms. Small arms is a subset of light firearms that is designed to be readily carried and operated by an individual. The term "firearm" is however variably defined in both technically and legally in different countries (see legal definitions), and can be used colloquially (sometimes incorrectly) to refer to any type of guns.

The first firearms originated in 10th-century Song dynasty China (see gunpowder weapons in the Song dynasty), when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, which was operable by a single person and was later used effectively as a shock weapon in the siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon, and the technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other explosive propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart a stabilizing spin to the bullet for improved external ballistics.

Fire arrows were one of the earliest forms of weaponized gunpowder, being used from the 9th century onward. Not to be confused with earlier incendiary arrow projectiles, the fire arrow was a gunpowder weapon which receives its name from the translated Chinese term huǒjiàn (火箭), which literally means fire arrow. In China, a 'fire arrow' referred to a gunpowder projectile consisting of a bag of incendiary gunpowder attached to the shaft of an arrow. Fire arrows are the predecessors of fire lances, the first firearm.

Later rockets utilizing gunpowder were used to provide arrows with propulsive force and the term fire arrow became synonymous with rockets in the Chinese language. In other languages such as Sanskrit, 'fire arrow' (agni astra) underwent a different semantic shift and became synonymous with 'cannon'.

The hand cannon (simplified Chinese: 火铳; traditional Chinese: 火銃; pinyin: huǒchòng or 手铳; 手銃; shǒuchòng), also known as the gonne or handgonne, is the first true firearm and the successor of the fire lance. It is the oldest type of small arms, as well as the most mechanically simple form of metal barrel firearms. Unlike matchlock firearms it requires direct manual external ignition through a touch hole without any form of firing mechanism. It may also be considered a forerunner of the handgun. The hand cannon was widely used in China from the 13th century onward and later throughout Eurasia in the 14th century. In 15th century Europe, the hand cannon evolved to become the matchlock arquebus, which became the first firearm to have a trigger.

Gunpowder weapons in the Song dynasty included fire arrows, gunpowder lit flamethrowers, soft shell bombs, hard shell iron bombs, fire lances, and possibly early cannons known as "eruptors". The eruptors, such as the "multiple bullets magazine eruptors" (bǎi-zi lián zhū pào, 百子連珠炮), consisting of a tube of bronze or cast iron that was filled with about 100 lead balls, and the "flying-cloud thunderclap eruptor" (fēi yún pī-lì pào, 飛雲霹靂炮), were early cast-iron proto-cannons that did not include single shots that occluded the barrel (thus called "co-viative" weapons). The use of proto-cannon, and other gunpowder weapons, enabled the Song dynasty to ward off its generally militarily superior enemies—the Khitan led Liao, Tangut led Western Xia, and Jurchen led Jin—until its final collapse under the onslaught of the Mongol forces of Kublai Khan and his Yuan dynasty in the late 13th century.

The siege of De'an (德安之戰) was fought as part of the Jin–Song Wars of China in 1132, during the Jin invasion of Hubei and Shaanxi. The battle between the besiegers, a group of rebels led by Li Heng and the Song Chinese defenders is important in global history as the first recorded instance of the fire lance, an early ancestor of firearms, being used in battle.