Wellll... Their was 3 causes or effects during at that point of time, sooo... The first one was some internal problems that made the country hard to rule, second is about the feudal system dying or more like decaying, whichever it's basically the same anywhooo, that also made the fractions grow, and lastly, finally, it's about reinstating the emperor that conformed that movement by using some old tradition that unified everyone for some reason.
