parts of Eastern Arabia. Archaeological evidence of Greek-influenced materials has been discovered in Qatar. Excavations north of Dukhan uncovered potsherds of Seleucid characteristic, and a cairnfield consisting of 100 burial mounds dating to the era was discovered in Ras Abrouq. The relatively large number of cairns suggest a sizeable sea-faring community prevailed in the area. After losing most of their territories in the Persian Gulf, Seleucid influence ceased in the area by c. 250 BC. Persian control (250 BC–642 AD) Following the eviction of the Seleucid by the Parthian Empire in c. 250 BC, the latter gained dominion over the Persian Gulf and Arabian Coast. As the Parthians were dependent on trade routes through the Persian Gulf, they established garrisons along the coast. Pottery recovered from expeditions in Qatar has demonstrated links to the Parthian Empire. Ras Abrouq, a coastal city north of Dukhan, housed a fishing station which foreign vessels used to dry fish in 140 BC. A number of stone structures and large quantities of fish bones were recovered from the site. Pliny the Elder, a Roman author, wrote an account on the inhabitants of the peninsula around the mid-first century AD. He referred to them as the "Catharrei" and described them as nomads who constantly roamed in search of water and food. Around the second century, Ptolemy produced the first known map to depict the landmass, referring to it as "Catura". In 224 AD, the Sasanian Empire gained control over the territories surrounding the Persian Gulf. Qatar played a role in the commercial activity of the Sasanids, contributing to at least two commodities: precious pearls and purple dye. Sasanid pottery and glassware were found in Mezru'ah, a city north-west of Doha, and fragments of glassware and pottery were discovered in a settlement in Umm al-Ma'a. Under the Sasanid reign, many of the inhabitants in Eastern Arabia were introduced to Christianity after the religion was dispersed eastward by Mesopotamian Christians. Monasteries were constructed in Qatar during this era, and further settlements were founded. During the latter part of the Christian era, Qatar was known by the Syriac name 'Beth Qatraye' (ܒܝܬ ܩܛܪܝܐ; "region of the Qataris"). A variant of this was 'Beth Catara'. The region was not limited to Qatar; it also included Bahrain, Tarout Island, Al-Khatt, and Al-Hasa. The dioceses of Beth Qatraye did not form an ecclesiastical province, except for a short period during the mid-to-late