ante diem vi idus decembres

Rites in honour of Tiberinus and Gaia -- not a lot is known about these rites; Tiberinus had a temple on the Tiber island and presided over the Tiber (of course); Gaia seems to have originally given the Campus Martius (a.k.a. Campus Tiberinus) to the Roman people.

65 B.C. -- birth of the poet Horace (Quintus Horatius Flaccus)