Sofia is the capital and largest city of the Republic of Bulgaria, with a population of 1,344,605 in the Capital Municipality. It is located in western Bulgaria, at the foot of the mountain massif Vitosha, and is the administrative, cultural, economic, and educational centre of the country. One of the oldest cities in Europe, the history of Serdica-Sredets-Sofia can be traced back some 7000 years ago - prehistoric settlements were excavated in the centre of the present city - near the royal palace, as well as in outer districts such as Slatina and Obelia. The well preserved town walls (especially their substructures) from antiquity date back before the 7th century BC, when Thracians established their city next to the most important and highly respected mineral spring, still functioning today. Sofia has had several names in the different periods of its existence, and remnants of the city's millenary history can still be seen today alongside modern landmarks.-------------Sofia was originally a Thracian settlement called Serdica, or Sardica, possibly named after the Thracian tribe Serdi. Around 500 BC another tribe settled in the region, the Odrysi, known as an ethnos with their own kingdom. For a short period during the 4th century BC, the city was ruled by Philip of Macedon and his son Alexander the Great. Around AD 29, Serdica was conquered by the Romans. It became a municipium, or centre of an administrative region, during the reign of Emperor Trajan (98-117)and was renamed Ulpia Serdica. It seems that the first written mention of Serdica was made by Ptolemy (around 100 AD). Serdica (Sardica) expanded, as turrets, protective walls, public baths, administrative and cult buildings, a civic basilica, an amphitheatre - the City Council (Boulé), a large Forum, a big Circus (Theatre) etc. were built. When Emperor Diocletian divided the province of Dacia into Dacia Ripensis (at the banks of the Danube) and Dacia Mediterranea, Serdica became the capital of Dacia Mediterranea. The city subsequently expanded for a century and a half, it became a significant political and economical centre, moreso - it became one of the first roman cities where Christianity was recognized as an official religion (Еmperor Galerius). So it was only very natural that Constantine the Great called Serdica (Sardica) "My Rome". ---------------- Serdica was of moderate size, but magnificent as an urban concept of planning and architecture, with abundant amusements and an active social life. It flourished during the reign of Byzantine Emperor Justinian I, when it was surrounded with great fortress walls whose remnants can still be seen today. The city was destroyed by the Huns in 447 but was rebuilt by Justinian and for a while called Triaditsa.