Thieves stole four ancient artefacts, including a 2,450-year-old golden helmet, from a museum in the Netherlands. The incident took place during the early hours of January 25 at Drents Museum in Assen. The stolen artefacts were given on loan to the Drents Museum by the National History Museum of Romania in Bucharest. They were part of an exhibition about the Dacians, an ancient society that inhabited present-day Romania before being conquered by the Romans. In a statement, Harry Tupan, Drents Museum’s general director, said, “This is a dark day for the Drents Museum in Assen and the National History Museum of Romania in Bucharest… We are intensely shocked by the events last night at the museum. In its 170-year existence, there has never been such a major incident.” Here is a look at the stolen golden helmet and how the thieves carried out the daring heist. What is the stolen 2,450-year-old golden helmet? Known as the Helmet of Coțofenești, the stolen solid-gold headpiece dates back to roughly 450 BCE. It was discovered by a child in 1929 in a small Romanian village. It subsequently “suffered some damage as it was used as a toy and later a water vessel for chickens,” according to a report by The Washington Post. The helmet, which weighs around a kilogram, is decorated with two large eyes in the front — above the user’s brow bone — has several mythological creatures engraved on it, and a male character holding a dagger and appearing to sacrifice a ram, the report said. Upon examination, experts realised that it was not an ordinary helmet and belonged to an unknown local Dacian king or a local aristocratic noble. The helmet is well-known in Romania, and has been noted in several history books and archaeological catalogues. It was also once re-created for a 1960s Romanian film called “The Dacians,” “which depicted the lead up to a destructive historical war between the Romanian Emperor and the Dacian Kingdom in 86-88 AD,” the WaPo report said. While authorities refused to put a price tag on the stolen artefacts, including the helmet, Romanian officials have called their value “incalculable” to Romania’s culture. How were the artefacts stolen? CCTV footage released by the police shows three hooded suspects trying to open an exterior door of the Drents Museum, and then an explosion and a flurry of sparks. According to the police, the thieves used explosives to blast their way into the museum. Authorities were informed about the incident around a half-hour later. They also received a report of a nearby car fire which might be connected to the crime. “A possible scenario is that the suspects switched to another vehicle in the vicinity of the fire,” the Dutch authorities said in a statement. So far, the suspects have not been identified. Dutch police said they are working with the global police agency Interpol and had, as of Sunday, received more than 50 tip-offs, according to a report by CNN.