This ring is thought to be an excellent piece of jewelry that dates back almost 2,000 years and was once owned by the notoriously despotic ancient Roman tyrant Caligula

A Sky-Blue 2,000-Year-Old Sapphire Ring - Fascinating Archaeological  Caligula Artifacts

This 2,000-Year-Old Sapphire Ring was Once Worn by Caligula

2,000-year-old sapphire ring that 'belonged to Roman Emperor' goes on sale  for £500,000 | Daily Mail Online