This book is concerned with the machinery of medieval siegecraft as used by Chinese, Mongol, Japanese and Korean armies. Almost all the machinery was initially developed in China, but each country provides its own context into which the siege engines were fitted, and distinctive differences reveal both strengths and weaknesses in the machines themselves, and also raise questions about cultural attitudes to siegecraft and even to the practise of war itself. This, the first volume, deals with the machinery of siege warfare prior to the introduction of gunpowder (though some earlier incendiary weapons are considered). The particular concept of Chinese siegecraft was the fortified town, which was where the wealth of Ancient China was located. Towns and cities were a lure and a target for rebels and raiders alike. These urban centres were reduced by an impressive array of machinery, including siege crossbows and catapults. In addition to walled towns on the Chinese model, Korea also possessed numerous sansong (mountain fortresses), characterised by a style of castle building that used flat stones to build walls that snaked up and down the contours of a mountain, structures that required different types of machine to conquer. In Japan, fortified places tended to be isolated military outposts rather than walled towns, and their siegecraft was also characterised by a minimal use of large-scale siege weapons. The Mongol influence brought with it many new siege weapons to East Asia, of which the most important was the Muslim counterweighted trebuchet, first used against the Song at the siege of Xiang Yang in 1272.