 The civil war during the year of the Four <unk> was described by ancient historians as a <unk> period . According to <unk> , this instability was rooted in the fact that emperors could no longer rely on the perceived legitimacy of the imperial bloodline , as <unk> and those before him could . <unk> began his short reign with the execution of many allies of <unk> and possible future enemies . One such notable enemy included <unk> <unk> , who claimed to be the son of Emperor <unk> . 
