 The medieval town was a key Bulgarian stronghold during Bulgarian tsar Samuil's wars against the Byzantine Empire in the 11th century, when it was governed by the local noble Krakra of Pernik, withstanding Byzantine sieges a number of times.Some places in Central Europe possibly named after Perun are the villages of Parndorf (formerly known as Perun) and Pernitz in the Parndorf Plain, Perná in Moravia, Beroun in Bohemia, and Pernek in Slovakia.Perun is strongly correlated with the near-identical "Perkūnas"/"Pērkons" from Baltic mythology, suggesting either a common derivative of the Proto-Indo European thunder god (whose original name has been reconstructed as Perkwunos), or that one of these cultures borrowed the deity from the other.