121: Meaning (information, definition, explanation, facts)

Events

• Era name changes from Yongning (2nd year) to Jianguang in the Chinese Eastern Han Dynasty.
• Roman settlement in present-day Wiesbaden, Germany is first mentioned.
• Roman emperor Hadrian fixes the border between Roman Britain and Caledonia on a line running from the River Tyne to the Solway Firth.

• April 26 - Marcus Annius Verus, later the Roman Emperor Marcus Aurelius

• Cai Lun, inventor of paper