<P> Grenades saw extensive use during World War I and later in World War II . The WW1 and WW2 era "stick grenade" was often used in trench warfare because the handle allowed it to be thrown farther, about 40 meters, though its explosive charge was generally smaller . The allies rather tended to use baseball grenades as they had a greater explosive force but were harder to throw (30 meters). </P> <P> The word "grenade" is likely derived from Old French pomegranate and influenced by Spanish granada, as the fragmenting bomb is reminiscent of the many - seeded fruit, together with its size and shape . Its first use in English dates from the 1590s . </P> <P> Rudimentary incendiary grenades appeared in the Eastern Roman (Byzantine) Empire, not long after the reign of Leo III (717--741). Byzantine soldiers learned that Greek fire, a Byzantine invention of the previous century, could not only be thrown by flamethrowers at the enemy, but also in stone and ceramic jars . Later, glass containers were employed . The use of Greek fire spread to Muslim armies in the Near East, from where it reached China by the 10th century . </P> <P> In China, during the Song Dynasty (960--1279AD), weapons known as Zhen Tian Lei (震 天 雷, "Sky - shaking Thunder") were created when Chinese soldiers packed gunpowder into ceramic or metal containers . In 1044, a military book Wujing Zongyao ("Compilation of Military Classics") described various gunpowder recipes in which one can find, according to Joseph Needham, the prototype of the modern hand grenade . The Chinese also discovered the explosive potential of packing hollowed - out cannonball shells with gunpowder . The mid-14th - century book Huolongjing (火龍 經, "Fire Dragon Manual"), written by Jiao Yu (焦 玉), recorded an earlier Song - era cast iron cannon known as the "flying - cloud thunderclap cannon" (飛 雲 霹靂 炮; feiyun pili pao). The manuscript stated that (Needham's modified Wade - Giles spelling): </P>

When were hand grenades first used in war
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