After reading a number of sources on the matter, it appears as much as certain that the Chinese historically invented gunpowder. There were instances of European claim with Roger Bacon who first wrote about it, and the assertion that guns were created by a German man who doesn't in fact exist. The primary argument against the Chinese inventing gunpowder is that there are only secondary sources citing primary Chinese sources. But gunpowder spontaneously appeared on the European stage and after the Chinese sources appeared. Is there any proof that the Chinese really didn't invent gunpowder?