Almost 2,000 gold coins, discovered by amateur divers near the port city of Caesarea in Israel, form the largest single hoard of medieval gold coins ever found in the country.

The hoard, dating from the Fatimid period (10th – 12th century CE), was found by a group of amateur divers who immediately reported the find to the Israel Antiquities Authority (IAA).

“The discovery of such a large hoard of coins that had such tremendous economic power in antiquity raises several possibilities regarding its presence on the seabed,” said Dr Kobi Sharvit, director of IAA’s Marine Archaeology Unit.

“There is probably a shipwreck there of an official treasury boat which was on its way to the central government in Egypt with taxes that had been collected. Perhaps the treasure of coins was meant to pay the salaries of the Fatimid military garrison which was stationed in Caesarea and protected the city.”

“Another theory is that the treasure was money belonging to a large merchant ship that traded with the coastal cities and the port on the Mediterranean Sea and sank there.”

The oldest coin in the hoard is a quarter dinar minted in Palermo, Sicily, in the second half of the 9th century CE.

Most of the coins belong to the Fatimid caliph Al-Hakim (996–1021 CE) and his son Al-Zahir (1021–1036), and were minted in Egypt and North Africa.

“The coin assemblage included no coins from the Eastern Islamic dynasties and it can therefore be stated with certainty this is a Fatimid treasure,” the archaeologists said.

“The great value and significance of the treasure become apparent when viewed in light of the historical sources. For example, the description of the traveler and geographer Ibn Jubayr who writes that the Muslim residents of the settlements were required to pay the Fatimid government half their agricultural produce at harvest time, in addition to payment of a head tax of one dinar and five carats (twenty-four carats equal one dinar, hence the method used to measure gold according to carats).”

“Descriptions in the Cairo Geniza from the 11th – 12th centuries CE tell, among other things, of the redemption of prisoners, including Jewish captives from Ashkelon who were transferred to Egypt. According to the documents, the Jewish community paid a sum of about 500 gold dinars to redeem and return them to Israel.”

“The coins are in an excellent state of preservation, and despite the fact they were at the bottom of the sea for about a thousand years, they did not require any cleaning or conservation intervention from the metallurgical laboratory,” said Dr Robert Cole, a numismatic expert at the IAA.

“This is because gold is a noble metal and is not affected by air or water.”

“The coins that were exposed also remained in the monetary circulation after the Crusader conquest, particularly in the port cities through which international commerce was conducted. Several of the coins that were found in the assemblage were bent and exhibit teeth and bite marks, evidence they were physically inspected by their owners or the merchants. Other coins bear signs of wear and abrasion from use while others seem as though they were just minted,” the archaeologists said.