Histiaeotis (Ancient Greek: Ἱστιαιῶτις, romanized: Histiaiōtis) or Hestiaeotis (Ἑστιαιῶτις - Hestiaiōtis) was a northwest district of ancient Thessaly, part of the Thessalian tetrarchy, roughly corresponding to modern Trikala regional unit. Anciently, it was inhabited by the Hestiaeotae (Ἑστιαιῶται), and the Peneius may be described in general as its southern boundary. It occupied the passes of Mount Olympus, and extended westward as far as Pindus. The demonym of the district's inhabitants is Histiaeotes (Ἱστιαιῶται, Histiaiōtai). In epigraphy, the regional name occurs as Hestiōtai, ambassadors in Athens and Histiōtai in the Thessalian grain decree for Rome (see Pelasgiotis) but most similarly written names are related to Histiaea, an Attic deme and a city in North Euboea. The epigraphical