The first known influenza pandemic occurred in 1580.
According to the Centers for Disease Control, as stated by Merriam-Webster, the first documented influenza pandemic struck in 1580. While earlier outbreaks might have occurred, this is the earliest one for which we have reliable records. Later, in 1743, an epidemic originating in Rome spread throughout Europe, introducing the term "influenza" to the British Isles (Flu Season: The History of ‘Influenza’ | Merriam-Webster www.merriam-webster.com › wordplay › influenza-flu-word-history-origin).
