Also known as "Ordos" crosses, from the region of China believed to have produced them, these unusual artifacts emerged only in the early part of the twentieth century. Christianity has had a long history in China, and Nestorians were welcome and active in China as early as the Tang dynasty (618-907 CE). However, it languished for centuries until the Yuan dynasty. Many members of the Mongol ruling family were Nestorian Christians, including Khubilai Khan's mother, as well as large numbers of the general northern population. One of Khubilai Khan's advisors was a Nestorian priest who traveled to Europe-the western-most reaches of the Mongol empire-on behalf of the Mongols. While the use of the items is not certain, each one has a small ring on the back, indicating they might have been used as ornaments, either on a belt or as a pendant. Given their appearance near grave sites, some scholars have suggested that they may have been used in funeral rites.