This article investigates the Bilecik region, which is located between Mysia, Bithynia and Phrygia in north-western Anatolia, during the pre-Hellenistic period, in the 1st millennium BC. The paper aims at understanding the cultural identities of people who inhabited the region by interpreting ancient sources, archaeological evidence and epigraphic data together. Moreover, it analyses the Vezirhan stele stylistically, which was found in the region during the early 1970s. Analogies have shown that the reliefs include both eastern and western elements and the stele has been proposed to be dated to the end of the 5th century BC. The Vezirhan stele with the Old Phrygian and Greek inscriptions and the Fıranlar stele, another Old Phrygian inscription, prove the Phrygian presence in the region. In addition to these, recent archaeological data, including the Iron Age settlements represented by the so-called "Phrygian Grey", imported wares and tumuli, is evaluated to shed light on the spread of the Phrygian culture, the settlement patterns and land use in the region. When all the data from the Bilecik region is evaluated, it can be understood that the southern half of the region was a part of the Phrygian core land. Despite the lacking consistent data from the northern part, the Phrygians might have inhabited small rural settlements or might have lived as nomadic tribes in the region.