The Vatican said on Sunday that it received a ransom demand for the return of two rare documents written by Renaissance master Michelangelo. The documents were stolen from the Vatican's archives nearly 20 years ago.
According to a Reuters report, the theft of the two documents had not been made public before Sunday.
Following a report by Rome newspaper Il Messaggero on Sunday, spokesman Federico Lombardi said a cardinal in charge of St Peter's Basilica had been contacted recently by a person who offered to get the documents back for what Father Lombardi called "a certain price".
Il Messaggero said the person, described as a former Vatican employee, had asked for 100,000 euros ($150,000). Here are five other times historical treasures were stolen.
1. Thousands of documents stolen from the United States National Archives and Record Administration
Some of these documents include the Wright brothers' original airplane patent, documents signed by French Enlightenment writer François-Marie Arouet known as Voltaire and some of the photographs taken by the first astronauts on the moon, Time magazine reported in October 2012.
Other missing items are an original patent filed by Orville and Wilbur Wright in 1903 for a "Flying Machine" and the bomb maps for Hiroshima and Nagasaki in 1945.
Time reported that most of the missing items wound up in the hands of unscrupulous collectors or in overseas black markets, making the retrieval of such documents difficult.
2. Priceless items stolen from palace in France
On March 1, 2015, thieves made off with 22 historic treasures inside a Chinese museum located in France, in just seven minutes. The priceless masterpieces housed in the nearly 900-year-old Fontainebleau palace included a jewel-encrusted crown of gold, silver goblets and Chinese cloisonne statuettes, according to France's Ministry of Culture.
This was the latest in a string of burglaries in the country by art thieves. The thieves covered their tracks by using foam from fire extinguishers. Also stolen was the Phra Maha Mongkut Longya crown, a miniature of the crown of King Mongkut, one of several gifts presented to Napoleon III by a delegation from Thailand when it was still known as Siam in 1861.
Made of gold, the crown was studded with 233 diamonds, 2,298 rubies, 46 emeralds and nine pearls. Other pilfered items were a rare Tibetan mandala ornament, a Qianlong-era cloisonne Qilin statuette, a Japanese sword and porcelain vases.
3. Egyptian museum robbed of more than 1,000 artefacts
In August 2013, RT.com reported that Malawi Museum, in the city of Minya, 300km from capital Cairo, was robbed. The thieves stole over 1,000 items, including a prized 3,500-year-old limestone statue, ancient beaded jewellery, gold and bronze Greco-Roman coins, and pottery and bronze-detailed sculptures of animals sacred to Thoth, one of the ancient Egyptian deities.
The museum's ticket agent was killed as the theft took place, Associated Press reported. By opening fire, archaeologist Monica Hanna who is also a security official, managed to save about 40 artefacts, including five ancient Egyptian sarcophagi, two mummies and several dozen other items that were left behind in the street by the thieves. Two other statues were also later returned.
4. A fossils dealer smuggled the bones of a 70-million-year-old type of dinosaur called the Tyrannosaurus bataar from Mongolia.
Eric Prokopi, a self proclaimed commercial palaeontologist was jailed for three months in a United States court for smuggling dinosaur fossils. Palaeontologists deal in science that studies fossil organisms and related remains. He pleaded guilty to illegally importing the fossilised remains of a Tyrannosaurus bataar skeleton in December 2012, the BBC reported.
The 70 million-year-old fossil was returned to its country of origin, Mongolia, where it had been extracted from the Gobi Desert, Forbes reported.
The BBC also reported that the New York court that had sentenced Prokopi heard that he had it at an auction in May 2012 for more than $1m (S$1.38m) but that it was then seized by the US government. Prosecutors said that from 2010 to 2012, Prokopi misrepresented the contents of dinosaur fossil shipments from Mongolia to the US. He also admitted illegally importing a Chinese flying dinosaur, two oviraptors and a duckbilled creature known as a Saurolophus.
5. French emperor Napoleon Bonaparte's hair, ring, stolen from museum
In April 2014, thieves broke into a museum in Australia and stole a lock of French emperor Napoleon Bonaparte's hair and other artefacts linked to him. Police said the thieves gained entry to The Briars museum in the south of Melbourne, through a bathroom window, British news site Daily Mail reported.
According to police, the burglars then "jemmied open cabinets" and stole artefacts linked to the military leader, including a glass frame containing Napoleon's hair, a ring and a snuff box. Also missing was a a ribbon inscribed by Napoleon in 1815.
The museum said the collection was put together by descendants of Englishman Alexander Balcombe, who met Napoleon when the Frenchman was exiled on the Atlantic island of St Helena from 1815 until he died, six years later.
