In the history of gunpowder there are a range of theories about the transmission of the knowledge of gunpowder and guns from Imperial China to the rest of the world following the Song, Jin and Yuan dynasties. The earliest bronze guns found in China date back to the 13th century, with archaeological and textual evidence for previous nascent gunpowder technology developed beforehand. Scholars note the scarcity of records for firearms in the Middle East prior to the mid-14th century, and in Russia before the late 14th century, yet cannons already appeared in Europe by the early 14th century. Less accepted theories include gunpowder as being independently invented in the Middle East or South Asia.