It emerged last week that a Portuguese Torah dating from the time of the Inquisition was discovered by a builder while demolishing a house in the small city of Covilhã.
The Hebrew scroll was found next to a 16th century church where descendants of Jewish converts were known to have worshipped.
After discovering the document, the builder wrapped it in a sheet and brought it home for safekeeping, where he kept it for 10 years.
About six months ago, he showed it to specialists, and it is currently on display at Covilhã's City Hall. When fully unravelled, it is 30m long and 60cm wide. It is in very fine condition and the letters are easily legible. The mayor of Covilhã plans to keep the scroll at the city's historical archive.
The scroll is an astonishing discovery because virtually all of Portugal's Jews were forcibly converted by King Manuel I in 1497 and, later, persecuted by the Inquisition. They and their descendants would have kept their Torahs and other religious books under great secrecy, and only worshipers in a very select circle would have been aware of the scroll's existence.
These converted Jews and their descendants were generally referred to as "New Christians" or "Conversos", or even "Marranos", meaning swine. They called themselves Anusim, however, meaning those who had been obliged to become Christians.
Anusim who wished to hold on to their Jewish beliefs and identities had to remain constantly on their guard because the Portuguese Inquisition - under the authority of the Catholic Church - was charged with arresting any of them who continued to practise Judaism.
A New Christian could be arrested for simply lighting candles on a Friday evening or whispering a word of Hebrew.
The Inqusition kept them in special prisons, often for years, and they were tortured in order to compel them to give up the names of other secret Jews. All their assets were confiscated by the church.
The Portuguese Inquisition lasted from 1536 until the 1770s, and those Anusim who wished to live openly as Jews fled the country whenever they could, establishing flourishing Portuguese-Jewish communities in North Africa, Italy, the Ottoman Empire and Holland. After the re-admission of Jews to England in the 1650s, they also started settling in London.