The Bessi (/ˈbɛsaɪ/; Ancient Greek: Βῆσσοι or Βέσσοι) were an independent Thracian tribe who lived in a territory ranging from Moesia to Mount Rhodope in southern Thrace, but are often mentioned as dwelling about Haemus, the mountain range that separates Moesia from Thrace and from Mount Rhodope to the northern part of Hebrus.Herodotus described them as a sort of priestly-caste among the Satrae, the Bessi being interpreters of the prophetic utterances given by a priestess in an oracular shrine of Dionysus located on a mountain-top.
In 72 BC, the proconsul of Macedonia Marcus Terentius Varro Lucullus defeated the Bessi in Thrace. Later Strabo, provides a record in which the Bessi are described as the fiercest of the independent Thracian tribes, dwelling on and around the Haemus range, and possessing the greater part of the area around that mountain chain. He calls them brigands among brigands and that they were addicted to plunder.
Mommsen says the capital of the Bessi was Uscudama now Edirne in modern Turkey but the real place seems to have been Bessapara, today Sinitovo near Pazardzhik, Bulgaria.