The connection between 666 and Nero comes from the theory that the number in the Book of Revelation is a coded reference to the Roman Emperor Nero Caesar. This is based on a practice called gematria, where letters are assigned numerical values. When the name "Nero Caesar," transliterated from Greek into Hebrew letters, is added up, the total is 666.
Gematria: An ancient system where letters of an alphabet are assigned a numerical value.
Nero Caesar: Roman Emperor from 54 to 68 AD who persecuted early Christians.
Calculation: The Greek version of his name, Neron Kaisar, is transliterated into Hebrew characters. The sum of the numerical values of these Hebrew letters equals 666.
Alternative number: A variation of this calculation, using the Latin spelling and a different Hebrew transliteration, results in the number 616, which appears in some ancient manuscripts of Revelation.
Historical context: This interpretation suggests John used a coded message to refer to Nero without directly naming him, which would have been dangerous for his followers.