On March 9, the Bulgarian Orthodox Church celebrates the day of the Holy Forty Martyrs. These are early Christian Armenian warriors, martyrs from the city of Sebase who died in the 4th century for their faith during the persecutions of Emperor Licinius.
According to popular belief, on this day the sun turns to summer and the weather warms up.
In the Bulgarian history, March 9, 1230 was the date of the battle at Klokotnitsa, when Tsar Ivan Asen II defeated and captured the invading Epirus ruler Theodore Comnenus. The Bulgarian tsar captured the whole family of Comnenus, and his numerous captured soldiers were released. In honour of the great victory, the tsar ordered the construction of a church to the Holy Forty Martyrs in the medieval capital the capital Tarnovo where he puts a commemorative inscription.