The headpiece Mr. Trump received is a replica of one of six gold crowns excavated from Gyeongju's royal tombs, alongside gilded jewelry, belts and other ornaments. The crown was excavated in 1973 from a tomb, known as the Cheonmachong, that researchers believe belonged to the 21st or 22nd Silla king. It is the "largest and most extravagant" of the six crowns, a spokesman for Mr. Lee told Mr. Trump during the ceremony.