These animations show the different dynasties and states that had been established in the land of China in the past.
These mainly used map resources from outside China (e.g. wiki japan), and represents the "lower bound" of the territories, especially in the north (Siberia)
These use some Chinese map sources, and tends to include the northern area, which though paying tribute to the emperor, was mostly tribal. (and I do not under where the Tang#5 map is from, likely from this site)
These are from Chinese source (mostly likely all based on a PRC Historical Map published in 1996, which was great （7 Vol, Edited by Tan Qishuang), except for the minor nuisance of "political correctness")
related: Curzon's various maps of historical evolution