Though those of us who grew up watching Indiana Jones may associate the Crusades with the quest to find the grail of eternal life, in reality they were among the deadliest and most brutal human undertakings of all time. Further proof of this has just been announced by the Israel Antiquities Authority (IAA), which has come to possess an ancient hand grenade thought to have been typical of the era.

The weapon is made from finely embossed clay, and would have been filled with a flammable liquid known as naphtha before being hurled at victims. Potentially dating all the way back to the 11th century, the grenade was capable of destroying entire ships.

The awesome explosive was handed over to the IAA by the family of Marcel Mazliah, who retrieved a host of ancient artifacts from the sea while working at the Hadera power plant on Israel’s Mediterranean coast. Following his death, his relatives contacted a representative of the IAA, who was staggered to find just how old some of Mr Mazliah’s treasures were.

According to Ayala Lester of the IAA: “The finds include a toggle pin and the head of a knife from the Middle Bronze Age (from more than 3,500 years ago).” The collection also includes pestles, mortars, and candlesticks thought to be around 1,000 years old.

“The items were apparently manufactured in Syria and were brought to Israel,” but fell overboard from a metal merchant’s ship, never to be seen again by human eyes until the inquisitive Mr Mazliah began scouring the ocean floor in search of ancient relics.

The Crusades themselves began in 1095 and ran until the end of the 13th century, resulting in the consolidation of Christianity under the authority of the Pope, and giving rise to many of the legends that continue to influence popular culture today.