The Abbey of Our Lady of Mount Zion, often referred to by modern authors as the Abbey of Sion or Order of Sion, was a small mediaeval monastic order which, according to a papal bull of the 12th century, had abbeys on Mount Zion in Jerusalem, on Mount Carmel, in Southern Italy (Calabria), and in France.
The French scholar Emmanuel Rey discovered the historical references to the Abbey of Our Lady of Mount Zion and published his findings in 1888.[1]
In Jerusalem, the Abbey's church was on Mount Zion, where it had been built on the ruins of an earlier Byzantine church, Hagia (Holy) Zion. The Abbey existed there for 200 years, one of many such small groups in Jerusalem during the city's occupation by the Crusaders. In the early 13th century, the Abbey's church was destroyed during a Muslim raid, and the monks moved to Sicily.
In 1617, the remaining monks joined with the Jesuit order.
Some forged "medieval" documents, created in the 1960s, manufactured a story about a fictional Priory of Sion, a supposed thousand-year-old secret society. In actuality, it was a local society created in 1956, but later elaborated into a massive hoax in France. As part of the hoax, various "medieval" documents were forged and planted in the French National Library. Known as the "Dossiers Secrets d'Henri Lobineau", they make mention of an "Order of Sion" from the Middle Ages, which allegedly founded the Knights Templar. In reality, no such historical monastic order by that name existed in Jerusalem during the Crusades, and any connection with the name of Abbey of Zion is purely coincidental. There is no historical evidence whatsoever that the Abbey of Zion had any connection with the Knights Templar.
The forged documents and the alleged link between the order and the Knights Templar figured in the plot of the novel The Da Vinci Code by Dan Brown. Part of the recent success of the hoax can be traced to an introductory note to the novel, which states that the documents and the link are established fact.
Other religious organisations bearing similar names, such as the Congregation of Notre-Dame de Sion are also unrelated to the medieval monastic order.[2]