ISIS Executes Syrian Scholar Who 'Refused' to Abandon Ancient City ISIS has reportedly killed one of Syria's most prominent historians.

 -- To those who knew him, Khaled al-Asaad was as much a part of the city of Palmyra as the ancient antiquities he died seeking to protect.

“The way he’d tell you the stories about Palmyra, you’d feel his passion for the city,” said historian Rim Turkmani, a close friend of al-Asaad and his family. “He had very profound knowledge, he spoke Aramaic, he could read the Palmyran Aramaic and read every inscription and tell you the story behind it.”

The 81-year-old Syrian historian was reportedly killed this week by ISIS militants occupying the ancient historical site, where he was the Director of Antiquities since 1963.

According to a statement from the Syrian Directorate-General of Antiquities and Museums, al-Assad was publicly beheaded, then militants suspended his body from the same Palmyran columns he had once restored.

“It’s very symbolic, the way he died is outrageous,” Turkmani told ABC News in a phone interview. “It’s not just that they killed him, the way they killed him, it’s a big message for everyone.”

Chris Doyle, the husband of Turkmani and Director of the Council for Arab-British Understanding, called the news “a dreadful shock in a conflict full of shocks.”

“He was 81, he posed no threat to anybody,” Doyle said. “He wasn’t politically active. He was an archaeologist.”

Al-Asaad spent his entire life in Palmyra. Turkmani said his lineage stretched back through the ancient city, giving him a unique personal perspective on the art he immersed himself in daily.

As ISIS advanced on the city, al-Asaad led the efforts to evacuate the city’s museum of many of its treasures. He then chose to stay behind.

Al-Asaad’s vast knowledge of the site extended to areas and items never displayed to the public, Turkmani said, making them more desirable to ISIS militants looking to profit from untraceable artifacts.

“If you grew up in Palmyra, the ruins are a part of your life and character,” Turkmani said. “Our suspicion is that he did not collaborate with them on further looting of more antiquities.”

ISIS took control of the city in mid-May, inciting an outcry from international community that the UNESCO World Heritage Site would be subject to looting and damage. It’s a reputation ISIS has developed in videos showing the destruction of museums and historical sites both in Syria and Iraq.

“For Syrians, to see Palmyra under the control of ISIS, it’s a devastation on the back of other devastations,” Doyle said. “The human loss of course is massive, but the cultural loss is too.”

State Department spokesman John Kirby condemned the killing of al-Asaad Wednesday afternoon, and remarked on how ISIS uses stolen antiquities to fund its terror network.

"We continue to urge all parties in both countries and in the international community to deprive ISIL of this funding stream by rejecting the trafficking and sale of looted artifacts," Kirby said. "These attempts to erase Syria's rich history will ultimately fail."