After he became ruler of Walachia in 1456, the 1st purposes of Vlad the Impaler were to sanction the order within the country and to fortify the state authority. Among more executive calls, Vlad The Impaler also started a powerful campaign against the burglars, thieves and law breakers who may be met everywhere : in the towns, on the primary roads or in the woods attacking the travelers, particularly the merchandisers. The troughness of Vlad the Impalers strategies has fast spread the fright in the country, so tha t the amount of breaches has shortly reduced.
There are far more views about the provenance of the impalement. File it under fiction, treat it for what it is, and you may just like it. Anything greater than that, and Id be surprised, but on the other hand.