The Church of Saints Constantine and Helen is the oldest church in Plovdiv, Bulgaria. It was built in 337 at the sight of an ancient pagan temple in the acropolis on one of the fortified hills. The church is named after Emperor Constantine the Great and his mother Helen.
According to tradition, this is the site of the martyrdom of Sts. Severian and Memnos together with 36 other holy martyrs of Plovdiv, who were martyred by beheading in 304 during the reign of Emperor Diocletian, near the eastern gate of the ancient city now located in Tsar Shishman Square. Their relics were once kept here and the church originally was dedicated to them. According to archaeologists and historians, the first church was built about 30 years following the martyrdom of these Saints. At some point in history, the name of the church came to be dedicated to Sts. Constantine and Helen.
In 1578 a German theologian described the church as the darkest in Plovidiv. By 1830 it was described as being in ruins with no roof, mainly due to constant destruction and rebuilding during Ottoman times. It was at this time that Todor Moravenov donated 200 grosha to rebuild the church, and locals from Bratsigovo rebuilt the church in 1832. Another eminent Revival period figure, Valko Chalakov, obtained a Sultan’s ferman granting permission to rebuild both St. Nedelya Church and Sts. Constantine and Helena Church. The newly built church was one of the largest of its time - 26m long, 18m wide and 8m high. Its magnificent frescoes and icons were painted by masters of one of the most famous Bulgarian Icongraphic Schools: the Debar School. Some of the icons and painting of the church were made by the famous Bulgarian National Revival painter Zahari Zograf who lived and worked in Plovdiv between 1834 and 1866. Unique also for Plovidiv is the iconostasis and fretwork in the Baroque style made by Joan Pashkula in Vienna. Later on, Nikola of Edirne and Stanislav Dospevski also painted icons for the church. In the period of 1894-1866 the walls were painted by Stefan Andonov and Atanas Gyudzhenov from Pazardzhik. They gilded the iconostasis and added polychrome decoration to the woodcarvings.
The church also contains a small icon of Sts. Constantine and Helen that is believed to be miraculous.
The Church of Sts. Constantine and Helen is included on the list of the 100 National tourist sites of Bulgaria and is the most visited by tourists Orthodox church in Plovdiv.