Ariel Schalit/AP Images

During a scuba dive in the shallow Mediterranean waters off Israel’s coast this past fall, Shlomi Katzin spotted an interesting shape on the sandy seabed. He swam closer, grabbed hold of it—and pulled up a sword.

But it wasn’t just any sword. The seashell-encrusted weapon (at right) is about 900 years old and likely belonged to a knight who fought in the Crusades!

The Crusades were a series of military campaigns that took place from 1095 to 1291, during the . Christian armies from Europe battled to push Muslim armies out of a region that both groups considered the Holy Land. (Today, that area is in Israel and parts of neighboring countries in the Middle East). 

Katzin also uncovered centuries-old stone anchors and pottery pieces. The suggest that Crusaders had anchored their ships near the shoreline as the soldiers fought. A knight may have dropped his sword or fallen into the water during a sea battle, historians say.

The ancient weapon is remarkably well preserved. Its iron blade is about 3 feet long, with its handle adding another foot. The sword weighs about 12 pounds, but it will weigh much less after the seashells and other marine organisms are removed. The Israeli government plans to display it in a museum.

“The sword . . . is a beautiful and rare find,” says Nir Distelfeld, an Israeli official. “It [takes] you 900 years back in time to a different era, with knights, armor, and swords.”