[Philip]

To further show the disconnect between tunkou and habaki, here are earlier examples demonstrating that the Chinese version is of Inner Asian origin. The left image is of a Khazar saber, 9th-11th cent. AD, of a form encountered in a wide expanse of western Asia and eastern Europe. The right one is from a Seljuk saber blade, 11th-12th cent., found in Iran. The feature lived on stylistically (chiseled into the blade, not a separate sleeve) into Mamlûk times (15th cent. Egypt). The tunkou does not appear on Chinese sabers until the end of the 16th cent. at earliest and started to fade from popularity in the 19th.