The Monastery of Saint Thaddeus is an ancient Armenian monastery in the mountainous area of West Azerbaijan Province. Also known as Kara Kilise and It is the best maintained of all Iran’s medieval churches.

According to Armenian Church tradition, the Apostles Thaddeus and Bartholomew traveled through Armenia in AD 45 to preach the word of God, where many people were converted and numerous secret Christian communities were established.

The ancient Christian historian Moses of Khorene told the following story, considered a legend by most modern historiographers. Thaddeus converted King Abgar V of Edessa. After his death, the Armenian kingdom was split into two parts. His son Ananun crowned himself in Edessa, while his nephew Sanatruk ruled in Armenia. About AD 66, Ananun gave the order to kill Saint Thaddeus in Edessa. The king’s daughter Sandokht, who had converted to Christianity, was martyred with Thaddeus. Her tomb is said to be located near the Qara Kelisa.