Forty Martyrs Church (Mor Behnam, Kırklar Kilisesi) was constructed in 569 and consecrated in honor of Syriac Saint Behnam and his sister. The name Forty Church and Mor Behnam, the church got both names from early Christian tradition. According to one tradition this church was built in the last quarter of the 4th ccnentury AD by Sanherib II the Governor of the Assyrians in remeberance of his son Behnam and daughter Sarra who died after they converted to Christianity by Mar Mattay.When the original Kırklar Church in Mardin was converted into a mosque in the 12th century, the name of Mor Behnam Church was changed to "Kırklar Church".
See:
- William Warda, Early Assyrian Churches and Monasteries in northern Iraq https://archive.ph/2013.01.02-050518/http://www.christiansofiraq.com/monastery.html