Funerary artifacts from the Daisenryo Kofun in Sakai City, Osaka, Japan, believed to be the tomb of 5th century Emperor Nintoku, have emerged for the first time since the tomb was accidentally opened in 1872. A small gold-plated knife and three fragmented of gilded armor were held unpublished in a private collection for years. They were acquired by Kokugakuin University from an art dealer in 2024.The knife has an iron blade and is encased by its original cypress sheath covered in gold-plated copper. Five silver rivets were found on the sheath, and X-rays found that the gilded copper plate was just .5mm thick. This was highly advanced technology at the time.Scientific analysis revealed the knifes wooden sheathmade from Japanese cypresswas encased in a gold-plated copper plate and secured with silver rivets. The iron blade is broken into two sections, measuring 6.9 cm and 3.7 cm, suggesting an original length of around 15 cm. Experts believe it was ceremonial rather than functional, noting that no other gold-plated small knives from fifth-century kofun burials have been documented.The armor fragments, measuring 34 cm, are made of iron coated with gold rather than the gold-plated copper once assumed from historical drawings. This revision underscores how modern materials science can refine our understanding of ancient craftsmanship.According to archaeologist Taro Fukazawa of Kokugakuin University, These are not everyday weapons. They were likely created specifically as burial offerings for the ruling elite, showcasing the extraordinary political and economic power of the Nintoku court.Their place of origin was identified by the original paper wrappings with the handwritten labels and seal of Kaichiro Kashiwagi, the builder who explored and patched up the tomb after a landslide exposed the forward section and collapsed its stone chamber in 1872. As a royal tomb, it was not open to excavation, so Kashiwagi documented what he found inside knives, armor, helmets, sword fittings, glassware before backfilling it. Until the objects emerged on the market last year, the grave goods could only be seen in Kashiwagis illustrations.For everyone but wealthy collector Takashi Masuda, that is, who just so happened to have had close ties to Kashiwagi. So now we know that he did not rebury everything he found. He looted at least some of it, apparently the smallest pieces.The keyhole-shaped tumulus is 486 meters (1595 feet) long, 300 meters (980 feet) wide at the widest point and 34 meters (112 feet) high. It is encircled by three moats. The keyhole kofun were the largest and most elaborate of the 20,000 kofun built between the 3rd and 6th century. The Daisenryo Kofun is one of only three ruled to be imperial mausolea by the Imperial Household Agency. The agency tightly manages the mound and nobody is allowed in it or on it; people are only allowed in and around the moats, which are popular fishing spots.The knife and armor fragments have been loaned to the Sakai City Museum for display. They will be exhibited there through September 7th.