ante diem xvi kalendas maias

ludi Cereri (day 5)

43 B.C. -- Octavian (the future emperor Augustus) is hailed as Imperator for the first time

69 A.D. -- suicide of the emperor wannabe Otho (this might have occured on April 17)

304 A.D. -- martyrs of Saragossa

1928 -- death of Jane Ellen Harrison (Prolegomena to the Study of Greek Religion among others)