 The Assyrians are credited with the introduction of horse cavalry in warfare and the extensive use of iron weapons by 1100 BCE.Assyrians were also the first to use iron-tipped arrows.The "Wujing Zongyao" ("Essentials of the Military Arts"), written by Zeng Gongliang, Ding Du, and others at the order of Emperor Renzong around 1043 during the Song dynasty illustrate the eras focus on advancing intellectual issues and military technology due to the significance of warfare between the Song and the Liao, Jin, and Yuan to their north.