During the late republic, the Fugalia, or Regifugium (February 24), was regarded as a kind of Independence Day, celebrating the expulsion of the last king from Rome and the beginning of the republic. However, the origin of this festival is likely something different. After the expulsion of Tarquinius Superbus in 510 BC, the office of Rex Sacrorum was created to continue the religious duties of the kings.

Confusion arose from an entry of the letters Q. R. C. F. in the calendars under 24 March and 24 May, which indicated Quando Rex Comitiavit Fas and meant that legal business could be transacted after the Rex Sacrorum had performed some ceremony in the comitium. The letters were wrongly interpreted as Quod Rex Comitio Fugerit, meaning the king fled from the assembly in the Forum.