When was Justinian only Crown Prince, his uncle the Emperor condemned him to death accused of plotting against the throne. A night, St. Sergius and St. Bacchus appeared in a dream to the Emperor and was told that it forgiveness to Justinian because he was innocent. In appreciation, When Justinian became emperor, he ordered the construction of a church in honor of the Holy protectors of the Byzantine troops. The current little Hagia Sophia (Küçük Ayasofya Camii in Turkish) It is the ancient Church of St. Sergius and St. Bacchus. Although it is locates just three hundred metres from the Hippodrome many visitors miss the oldest Byzantine Church that remains in foot in Istanbul.
Like Hagia Sophia, it was built by Justinian, and probably by the same architects, Isidore of Miletus and Anthemius of Tralles. Due to the similar exterior, for a long time it was thought that the building, completed in the year 536, was a trial of the design and techniques to be used later in Santa Sofia but the structure of both buildings is very different and today the idea has been discarded.
To go to the little Santa Sofia we have to go down to the sea from the end of the Hippodrome where is the Rectorate of the University of Marmara. The Church is located next to the railway and is surrounded by pleasant gardens. Fifty years after the conquest of Constantinople it was converted into a mosque and then several sultans and viziers expanded it and repaired. Later on the madrasa, the current portico, the fountain for ablutions and the small minaret were added. We also find a small Ottoman cemetery and the tomb of Hüseyin Ağa. The complex offers craft shops, flea books market and also a coffee place.
Earthquakes, periods of abandonment and the construction of the railroad caused much damage to the building over the centuries. As it is built so close to the sea of Marmara, the Church always suffered moisture. Inside we can look at the result of the last restoration which was completed in 2006 and there is almost nothing kept of the rich golden Byzantine mosaics and floor, however, we can enjoy the green and black marble columns with the monogram of Justinian and Theodora in their rich capitals that keep the unmistakable Byzantine taste of the monument. The walls are covered with white in combination with blue and adorned with Turkish and calligraphic motifs.
The dome is very curious because it is divided into sixteen sections, eight are flat and the other eight concave. This octagonal design served as an inspiration to the imperial architect Mimar Sinan for the mosque of Rustem Pasha, well known for its superb tiles. It is surprising that the dedication of the Church to St. Sergius is still visible. The Greek inscription is written in relief over the columns and surrounds the nave in which five times a day Muslim believers pray. Another of the stunning realities of this country.
http://es.wikipedia.org/wiki/Iglesia_de_San_Sergio_y_San_Baco
http://www.theguideistanbul.com/news/view/291/kucuk-aya-sofya/