During the Second World War, a group of historians, curators and professors risked life and limb to protect Europe’s art and culture from Nazi plunderers. It is because of these ‘monuments men’ and women that future generations can appreciate works such as Michelangelo’s sculpture Madonna of Bruges, Johannes Vermeer’s painting The Astronomer and countless others.

The murder of the Syrian archaeologist Khaled al-Asaad last week is a brutal reminder of the risks that professionals have taken to protect the world’s cultural heritage. Al-Asaad was known as ‘Mr Palmyra’ for his more than 40 years of work at that Roman Empire site in Syria. It is now occupied by Islamist militants, who last Sunday destroyed one of its temples. Al-Asaad was killed in part because he would not reveal the location of hidden artefacts, according to news reports. A week before, museum official Qasem Abdullah Yehiya was killed in a rocket attack on the Damascus Citadel and the National Museum of Damascus.

Across Syria and Iraq, a new generation of cultural guardians are risking their lives to safeguard museums, archaeological and other cultural sites from destruction and to document the damage. Their task is enormous. The destruction by Islamist terrorist group ISIS of sites such as the ancient Assyrian city of Nimrud has commanded most headlines, but its embrace of organized looting is just as great a threat. The collapse of civil society in Syria and Iraq has left hundreds of archaeological sites unguarded and susceptible to looting, encroachment and neglect.

Most of the protection efforts are necessarily secretive, but the stories that have emerged are truly heroic. Earlier this year, a group of Syrian professionals and volunteers secured a collection of Roman and Byzantine mosaics from the third to sixth centuries ad at the Ma’arra Mosaic Museum, near Aleppo, Syria. In February, The Wall Street Journal profiled a secretive band of Syrian academics who catalogue archaeological sites and track looted artefacts, sometimes donning disguises.

All of us who find inspiration in the cultural history of humanity, now and in the future, owe a huge debt to the sacrifices of these people.