Ras (Serbian Cyrillic: Рас, Latin: Arsa), known in modern Serbian historiography as Stari Ras (Стари Рас; meaning Old Ras), was one of the first capitals of the medieval Serbian state of Raška, and the most important one for a long period of time. Located in today's region of Raška, the city was right in the centre of the early medieval state that started to spread in all directions. It was founded between 8th and 9th centuries and got deserted sometime in the 13th century. Its favorable position in the area known as Old Serbia, along the Raška gorge, on the crossroads between the Adriatic Sea and state of Zeta, Bosnia in the west and Kosovo in the east added to its importance as a city. There is an impressive group of medieval monuments consisting of fortresses, churches and monasteries. The monastery at Sopoćani is a reminder of the contacts between Western world and the Byzantine world. Today the city lies in mostly unenclosed and unprotected ruins close to the city of Novi Pazar, which probably began its own life as a trading enclave for Ras. However, there are plans for future reconstruction of the site. The site of Stari Ras, in combination with the nearby Monastery of Sopoćani, is already a UNESCOWorld Heritage Site, and Stari Ras monastery (12th century) is being reconstructed and it too may be included on the UNESCO World Heritage List with the site. Stari Ras and Sopoćani World Heritage site is not far from another UNESCO World Heritage Site of Serbia, the magnificent medieval monastery and churches of Studenica. The 4th century Church of Saint Apostles Peter and Paul is one of the oldest in the Balkans.
With the arrival of Slavs beginning in the 520s, the Byzantine (Roman - "castellum of Arsa") town Arsia soon became a peripheral place for Serbia, as it served as the capital in the early and high Middle Ages (ca 880-960). In the early stages of Serbian statehood it was the easternmost town, bordering the First Bulgarian Empire, also annexed by the Bulgars in 924-927.
After the fall of the Bulgarian Empire (1018), Ras became the political center of Serbia. In the chrysobulls of Basil II dated to 1020, the Ras bishopric is mentioned as serving the whole of Serbia, with the seat at the Church of Saint Apostles Peter and Paul. Ras was part of the Ohrid archbishopric (1029), and was briefly seat of the Ras catepanate, a Byzantine administrative unit of the conquered Serbian territories. During the first Hungarian-Byzantine War (1127-9), the Serbs fought on the Hungarian side, re-conquering Ras which had been under Byzantine rule. In the next war (1149–51) the Byzantines seized Ras again.