The earliest surviving gun has been excavated in Manchuria, it is more than a foot long, has an even bore, and dates from 1288. One can presume therefore, that guns evolved prior to that date in China, perhaps around 1250.

The earliest evidence of a gun in Europe is a picture of a bombard which fired arrows, depicted in a 1327 manuscript in a library at Oxford.

The likeness of European and Chinese guns are so striking that it seems likely that actual guns were transported to Europe for actual copying after the vast Mongol empires had opened the trade roues between East and West.