<P> The earliest confirmed employment of the fire lance in warfare was by Song dynasty forces against the Jin in 1132 during the siege of De'an (modern Anlu, Hubei Province), where they were used to great effect against wooden siege towers called "sky bridges": "As the sky bridges became stuck fast, more than ten feet from the walls and unable to get any closer, (the defenders) were ready . From below and above the defensive structures they emerged and attacked with fire lances, striking lances, and hooked sickles, each in turn . The people (i.e., the porters) at the base of the sky bridges were repulsed . Pulling their bamboo ropes, they (the porters) ended up drawing the sky bridge back in an anxious and urgent rush, going about fifty paces before stopping ." The surviving porters then tried once again to wheel the sky bridges into place but Song soldiers emerged from the walls in force and made a direct attack on the sky bridge soldiers while defenders on the walls threw bricks and shot arrows in conjunction with trebuchets hurling bombs and rocks . The sky bridges were also set fire to with incendiary bundles of grass and firewood . Li Heng, the Jin commander, decided to lift the siege and Jin forces were driven back with severe casualties . </P> <P> The siege of De'an marks an important transition and landmark in the history of gunpowder weapons as the fire medicine of the fire lances were described using a new word: "fire bomb medicine" (火炮 藥), rather than simply "fire medicine ." This could imply the use of a new more potent formula, or simply an acknowledgement of the specialized military application of gunpowder . Peter Lorge suggests that this "bomb powder" may have been corned, making it distinct from normal gunpowder . Evidence of gunpowder firecrackers also points to their appearance at roughly around the same time fire medicine was making its transition in the literary imagination . Fire lances continued to be used as anti-personnel weapons into the Ming dynasty, and were even attached to battle carts on one situation in 1163 . Song commander Wei Sheng constructed several hundred of these carts known as "at - your - desire - war - carts" (如意 戰 車), which contained fire lances protruding from protective covering on the sides . They were used to defend mobile trebuchets that hurled fire bombs . </P> <P> Gunpowder technology also spread to naval warfare and in 1129 Song decreed that all warships were to be fitted with trebuchets for hurling gunpowder bombs . Older gunpowder weapons such as fire arrows were also utilized . In 1159 a Song fleet of 120 ships caught a Jin fleet at anchor near Shijiu Island (石臼 島) off the shore of Shandong peninsula . The Song commander "ordered that gunpowder arrows be shot from all sides, and wherever they struck, flames and smoke rose up in swirls, setting fire to several hundred vessels ." Song forces took another victory in 1161 when Song paddle boats ambushed a Jin transport fleet, launched thunderclap bombs, and drowned the Jin force in the Yangtze . </P> <P> According to a minor military official by the name of Zhao Wannian (趙 萬年), thunderclap bombs were used again to great effect by the Song during the Jin siege of Xiangyang in 1206 - 1207 . Both sides had gunpowder weapons, but the Jin troops only used gunpowder arrows for destroying the city's moored vessels . The Song used fire arrows, fire bombs, and thunderclap bombs . Fire arrows and bombs were used to destroy Jin trebuchets . The thunderclap bombs were used on Jin soldiers themselves, causing foot soldiers and horsemen to panic and retreat . "We beat our drums and yelled from atop the city wall, and simultaneously fired our thunderclap missiles out from the city walls . The enemy cavalry was terrified and ran away ." The Jin were forced to retreat and make camp by the riverside . In a rare occurrence, the Song made a successful offensive on Jin forces and conducted a night assault using boats . They were loaded with gunpowder arrows, thunderclap bombs, a thousand crossbowmen, five hundred infantry, and a hundred drummers . Jin troops were surprised in their encampment while asleep by loud drumming, followed by an onslaught of crossbow bolts, and then thunderclap bombs, which caused a panic of such magnitude that they were unable to even saddle themselves and trampled over each other trying to get away . Two to three thousand Jin troops were slaughtered along with eight to nine hundred horses . </P>

Who introduced the gun power in the indian subcontinent