The gold coin, which dates from 42 B.C. and is valued at $4.2 million, is thought to have been looted from a field near where an army loyal to Brutus camped during the struggle for control of Rome.

An ancient Roman coin celebrating Julius Caesar’s death has set an auction record. Last Thursday, the ultra-rare gold coin, dating back more than 2,000 years, sold to an anonymous bidder for a ...