 Due to the lack of written sources on this period , much of <unk> 's life has remained obscure . The most substantial surviving account of the reign of <unk> was written by the 3rd @-@ century historian <unk> <unk> . His Roman History , which spans nearly a millennium , from the arrival of <unk> in Italy until the year <unk> , was composed more than one hundred years after <unk> had died . Further details are added by an abridged biography from the <unk> de <unk> , a work alleged to have been authored by the 4th @-@ century historian Aurelius Victor . 
