But the prosperity and enrichment of the beautiful city did not attract peaceful settlers only. It was often attacked and plundered during the Great Movement of the Peoples and enjoyed its ultimate ”Golden Age” during the period of the Eastern Roman Empire - Byzantium during the reign of the emperor Justinum I (527-565).

Serdika has been Bulgarian since 809 when Khan Krum desired the city and forced the Byzantine garrison to surrender the town. In medieval Bulgaria the city assumed the name Sredets and became one of the most eminent and important fortifications of that time.

During Byzantine rule the city was called Triaditsa. In 1185 part of the Bulgarian lands were liberated from Byzantine rule and the city became Bulgarian once again in 1194. The city acquired its present-day name of Sofia during the 14th century.

According to the First Construction of the Principality of Bulgaria - the highest governing power is assigned to the National Assembly (the Parliament). The building of the National Assembly is the work of the Bulgarian-born architect from Vienna, Konstantin Ivanovich. Its construction is completed in 1884, the official inauguration of the building takes place on November 26th, 1884. The building is a simple, massive structure with a central facade where Rennaissance and Baroque-style ornaments can be seen. Over the official entrance is the inscription: “Unification Makes Power” - this is the motto of those in power and it is also the will of the people. In 1890 additional premises are built next to the main structure, where the offices of the authority in power are housed. The National Assembly of the Republic of Bulgaria has been occupying this building to the present.

When Sofia is declared capital of Bulgaria, a quick decision has to be taken as to where the Bulgarian Knyaz Alexander I Battenberg is to reside and work. The Sofia “Konak” (a building built during the 16th century, which during Ottoman rule served as town hall and police headquarters simultaneously) is chosen. The reconstruction and transformation of the building into a palace starts in 1889 under the supervision of the Viennese architect Ruppelmaier. The west wing houses the new representative premises, while the ground floor preserves its initial state. A vast marble staircase is constructed in the northern part of the “Konak”. This staircase allows access into the large halls where state receptions and festivities are held. In 1887 the Viennese architect Fridrich Gruenanger adds an additional structure to the northeastern part of the building. It houses the residential quarters of the royal family. The influence of the Viennese Baroque is felt in the interior and exterior design of this two-storey building. The numerous gypsum Roccoco elements on the walls and ceilings are the creation of the Viennese sculptor Greis. Today, the palace houses the National Art Gallery and the National Ethnographic Museum.

Another representative building, mainly used for ceremonial purposes, balls, stately receptions and concerts by the Bulgarian government and the Knyaz is the Military Club. Its constructions starts in 1895 and its project is the work of the Czech architect Kolar. It is completed in 1907, the facade is Rennaissance in style and is the creation of the sculpture M. Vassilev. In the beginning of the 20th century this is one of the most imposing buildings in Sofia.

Other buildings serving the authority in power, which are used for the same purposes today are situated in the city center and are build in the period       1922-1937. Examples of these are Ministry of Defence (1925-1937) and Ministry of Justice. These are in compliance with the project of the architects Kolar and Marinov.

The Ministry of Justice (1937) after the project of the Bulgarian architect Papazov is of great interest whit its stained glass decoration, the work of the artist Ivan Petkovv, depicting the goddess of justice Temida.

Political changes take place in Bulgaria after the 9th of September 1944 when the country becomes a republic. The political power is taken over by the Fatherland Front and the Bulgarian Communist Party plays a leading role in the governing power. This has its influence on the architecture of the city centre. A massive building complex is built in the urban Stalinistic style. Today these buildings house the Council of Ministers, the Party House where parliamentary commissions work and where the presidency is.

Eastern Orthodox Christianity is the official religion of the Bulgarian population after the liberation of Bulgaria from the Ottoman rule. The Eastern Orthodox Church gains the status of an independent patriarchate in 1953 and is administrated by the Saint Synod, headed by a patriarch. The Synod Palace was built during 1906-1910 after the projects of the architects Momchilov and Milanov. Of great value is the mosaic illustration of element Bulgarian intellectuals of the enlightenment period, who contributed greatly to the winning of independence of the Bulgarian church in 1870 when Bulgaria was still under Ottoman rule. The creative skills of Professor Hristo Tatchev were put into this exclusive ceramic mosaic work. The prototype of the patterns of colours were taken from the ”Golden Church” in Preslav (the capital of the Second Bulgarian Kingdom).

Another very imposing landmark of Sofia is the St.Alexander Nevski Cathedral,declared in 1953 as cathedral of the patriarh. The temple was built by the grateful Bulgarian people and it honoured the Russian Tsar Alexandet I the Liberator. The church was named after the spiritual patron of the Russian Tsar-Saint Alexander Nevski. In 1880 the Kniaz issued a proclamation addressed to the Bulgarian people asking them for donations for the construction of this holy shrine. It takes eight years to build the cathedral (1904-1912) and its architectural plans are carried out by a joint Russian-Bulgarian team of architects under the supervision of the Russian architect Pomerantsev.

The cathedral is a 5-nave Byzantium-style basilica structure and encompasses 3170 square metres of space. Five thousand people can stand inside during mass, its belfry is five metres high and has twelve bells cast in Moscow, all weighing 23 tons. The interior decoration of the temple includes such materials as: multicoloured Italian marble, Brazilian onyx, alabaster etc. The temple’s wall murals are the work of Bulgarian and Russian artists among which are Professor Vasnetsov, Myasoedov, Anton Mitov, Goergi Zheliazkov and Ivan Murkvichka.

The patriarch’s throne is made of wood and its woodcarving is typically Bulgarian. The exclusive acoustics of the cathedral turn mass into an incredible experience.

The buildings of the supreme authority are concentrated in the centre of the city. Most of them were created at the end of the 19th and beginning of the 20th century. Immediately after the liberation of Bulgaria from Ottoman rule the influence of the Vienna school of architecture and Viennese traditions could be felt, but as Bulgarian state authority became stronger, the architectural projects and artistic work of many Bulgarian construction specialists , artists and sculptors prevailed.