On this day in AD 69, Roman general Titus Flavius Vespasianus entered Rome, becoming emperor and putting to an end the "year of the four emperors" which saw short-lived rule by:
As an example of his take-no-prisoners attitude, he had the Colosseum built during his reign. On the site of Nero's old Golden Palace. New boss in town, different than the old boss.
And oh yeah, in 1803, the United States purchased Louisiana from the Emperor of France, setting up a whole bunch of folks for misery during hurricane Katrina. I blame George W. Bush.