The Serapia or Sarapia was a Roman Imperial religious festival devoted to the Greco-Egyptian god Serapis. It is found as an official holiday on 25 April as late as the Calendar of Filocalus in 354 AD. In farmers' almanacs (menologia rustica) dating to the first half of the 1st century, the day was a sacrum or rite for Serapis along with Isis Pharia,[1] "Isis of the Lighthouse (Pharos) of Alexandria".[2]