eople may have originally made them to record information and convey messages before people started to write. One hundred thousand year old tools have been discovered that were probably used to tie and untie knots, and there is a reference to knots in ancient literature. But it isn't known when they first started to be used symbolically or woven for art.
It is known that there were used for artistic decoration and to symbolize and express thoughts and feelings in the Tang Dynasty era (618-907). The Tang Empire was a large one that covered most of regions of modern China, and the traditional art form was carried on by succeeding generations as part of their culture.
Ancient and Modern Use of Artistic Knots