The Islamic State (ISIS/ISIL) destroyed the 4th century Mar Behnam Catholic monastery in Iraq on Thursday. The terrorists have vowed to erase all Christian history within their territories conquered in the Middle East.

Images on social media show a large explosion near the tombs “of Mar (Saint) Behnam and Mart (Saint) Sarah” in Qaraqosh, which is just southeast of Mosul. Kurdish journalists traveled to the area and confirmed the destruction.

Assyrian pagan King Sennacherib II built the monastery in the 4th century in honor of his children Behnam and Sarah. Behnam converted to Christianity after he met the monk Mar Mattai. Behnam then brought his sister Sarah to the monk, who healed her leprosy. The miracle caused her to convert as well. Sennacherib, dismayed by their conversion, demanded his children denounce their new faith. Both resisted and he murdered them. Sennacherib regretted his decision later in life. Mar Mattai baptized the king. The monastery is built on the location where Mar Mattai healed Sarah.

“I didn’t want to see the pictures,” cried Dr. Nicholas al-Jeloo, an expert in Assyrian monasteries. “This is terrible. I’m in shock. This story intimately connects us to the ancient Assyrian heritage.”

The monastery is credited with helping to expand Christianity in the area. The Syrian Orthodox Church took care of the monastery with sculptures that date back to the 10th century. There are no details regarding whether the militants took the sculptures, which they are known to do. The monastery is also reportedly home to “precious and rich Syrian and Arabic manuscripts.”

“The place is a major site of pilgrimage, at the very origins of Christianity in the region, and it links us to our ancient Assyrian heritage – being only a stone’s throw from the ruins of Nimrud, also destroyed by Isis,” continued al-Jeloo. “The only way I could describe it is as a work of art. It was one of the most richly carved monastery complexes in northern Mesopotamia up until today.”

The Islamic State took over the monastery in July 2014, a month after they captured Mosul. The militants threw out the monks and did not allow any of them to save the precious sculptures.