The capital of the Republic of Bulgaria is the city of Sofia (1 096 389 inhabitants, 550 metres above sea level). The city lies in the Sofia Plain, enclosed by the Balkan Mountains to the north, the Lozen Mountain to the southeast, Mountain Vitosha to the south, the Lyulin Mountain to the southwest.

The the plain is open to the northwest in the direction of Yugoslavia, and to the southeast to the Thracian Lowland. Sofia is situated 55 km from the Yugoslav border at Kalotina checkpoint, 113 km from the Gyueshevo checkpoint with Macedonia, 183 km from the Greek border at Koulata, 315 km from the Turkish border at Kapitan Andreevo, 211 km from the Romanian border at Vidin, 324 km at Rousse, 392 km from our maritime border at the port of Bourgas, and 470 km from the port of Varna. In close proximity to the capital city lie Pancherevo Lake and Iskar Dam. The Iskar River flows by the city, and several smaller rivers cross the city, the most popular of these being the Vladaya and the Perlovo Rivers.
Sofia is linked by international routes with the capitals of Europe, and via Istanbul and Ankara, with the Middle East.
History: Sofia is a city with a 7000-year history, which makes it a unique phenomenon in Europe, and places it among the settlements dating back to most distant antiquity. To this very day excavations in Sofia downtown bring up objects of the Neolithic man, and remnants of the Stone and Bronze Era. The reason why settlements arose so early is the abundance of thermal springs in the Sofia Plain. They cluster mainly around today’s city centre - near the old mineral baths, around the Presidency building, in Lozenets Quarter, and in Gorna Banya and Knyazhevo Quarters. The water temperature varies between 21o C and 42 o C, and they are curative, because of the significant amount of ions and mineral salts dissolved in them.
The first known tribes to settle in the plain were the Thracians from the triabe of Serdi. They gave Sofia its first name - Serdica.
Around 500 BC another tribe settled here, the Odrissi, known as a ethos having a kingdom of their own. For a short period during the 4th BC the city was in possession of Philip of Macedonia and of his son Alexander the Great. As late as in the year 29 AD Sofia was conquered by the Roman legions, and during the reign of Emperor Trayan (98-117) became the centre of an administrative region. It was given the name of Ulpia Serdica as a municipium, i.e. a centre of administrative region. Construction on the territory of the city expanded - turrets, protective walls, public baths, administrative and cult buildings, a civic basilica and a large amphitheatre, called bulevterion were built. In the 2nd century AD Sofia became the centre of the Lower Dacia province. It subsequently expanded for a century and a half, so that Constantine the Great came to call it “my Rome”. The city was of moderate size, but magnificent as an urban concept of planning and architecture, abundant in amusements and of active social life. The city flourished during the reign of Emperor Justinian when it was surrounded with great fortress walls, remains of which can be seen even today.
Fully preserved and well restored now is the Roman Rotunda, transformed into the Early Christian Church of St. George; it now stands behind the Sheraton Hotel. Attila took the city by storm in the 5th century. After his death the Byzantine Empire recovered it. It remained part of the Eastern Roman till the early 9th century AD.

When the kingdom of Danubian Bulgaria was founded in 681 AD, many Bulgarian khans coveted Serdica. But it was only in the year of 809 that Khan Kroum succeeded in conquering and including it in the Bulgarian territory. The new name of the city was changed to Sredets, which in the parlance of that time meant “middle, central part, centre”. Actually its location gave it all grounds to be considered the centre of the Balkan Peninsula. The city existed until the year 1018 AD when Bulgarian lands fell under Byzantine rule and it was renamed Triyaditsa, which meant “between mountains”. After 1194 the city regained its former name.
The city was repeatedly besieged and attacked by Magyars, Serbs and Crusaders. After the liberation of Bulgaria from Byzantine rule it was re-included in the territories of the country. Its name was now Sophia. The St. Sophia Church, which stands to this day next to the St. Aleksander Nevski Memorial Cathedral, gave the city its present-day name.
Sofia quickly expanded and became a centre of crafts and trade. New buildings and numerous churches were built in the city and the neighbouring villages, the best known of these is the Boyana Church.