Editing Dao (Chinese sword) (section)

==Early history==
[[File:Han iron weapons 01.jpg|thumb|right|[[Han dynasty]] steel ring-headed dao of different sizes (bottom).]]
The earliest dao date from the [[Shang dynasty]] in China's [[Bronze Age]], and are known as ''zhibeidao'' (直背刀)&nbsp;– straight-backed knives. As the name implies, these were straight-bladed or slightly curved weapons with a single edge. Originally bronze, these weapons were made of iron or steel by the time of the late [[Warring States]] period as metallurgical knowledge became sufficiently advanced to control the carbon content. Originally less common as a military weapon than the ''[[jian]]''&nbsp;– the straight, double-edged blade of China&nbsp;– the dao became popular with [[cavalry]] during the [[Han dynasty]] due to its sturdiness, superiority as a chopping weapon, and relative ease of use&nbsp;– it was generally said that it takes a week to attain competence with a dao/saber, a month to attain competence with a ''qiang''/spear, and a year to attain competence with a ''jian''/straight sword. Soon after dao began to be issued to infantry, beginning the replacement of the ''jian'' as a standard-issue weapon.<ref name="Tom 2001 207">{{harvnb|Tom|2001|p=207}}</ref><ref>{{harvnb|Graff|2002|p=41}}</ref> Late Han dynasty dao had round grips and ring-shaped pommels, and ranged between 85 and 114 centimeters in length. These weapons were used alongside rectangular shields.{{sfn|Lorge|2011|pp=69–70}}

By the end of the [[Three Kingdoms period]], the single-edged ''dao'' had almost completely replaced the ''jian'' on the battlefield.{{sfn|Lorge|2011|p=78}} The ''jian'' subsequently became known as a weapon of self-defense for the scholarly aristocratic class, worn as part of court dress.{{sfn|Lorge|2011|pp=83–84}}