ludi Florales ... a.k.a. Floralia (day 1) -- a festival originally ordered in response to an interpretation of the Sybilline books in 238 B.C., it fell into desuetude only to be revived in 173 B.C.; it was a general festival of drinking and other merriment in honour of Flora, who presided over (of course) flowers and their blossoms (Chloris is also mentioned ... I'm still trying to figure that one out).
4977 B.C. -- birth of the universe, according to the calculations of Johannes Kepler
399 B.C. -- death of Socrates (by one reckoning)
1753 -- birth of Edward Gibbon
1870 -- Heinrich Schliemann 'discovers' Troy