Compared to other stretches of the eastern frontier, northeastern Anatolia has rarely attracted the attention of scholars of the Roman and late antique periods. The region is known, through late antique written sources, to have housed a belligerent confederation of tribes, the Tzani, who lived off raids conducted against their neighbours. Until the fifth century AD, the Roman approach to the Tzanic problem was one of quiet co-existence, but, in the early sixth century AD, after war broke out again with Persia, necessity moved the emperor Justinian (r. AD 527–565) to intervene more actively against the Tzani. According to the sixth-century historian Procopius, the Tzani were subdued and a chain of forts was constructed in their lands to protect access to the Black Sea coast. The remains of these forts, as well as those of other sixth-century AD infrastructure allegedly built under Justinian, are still elusive. Nonetheless, evidence on the ground and in the written sources can still help investigate the nature of the Justinianic frontier defensive system.