Over a timespan of approximately 1400 years, from the New Kingdom of Egypt to the Ptolemaic Period, at least sixty Apis are attested to have been interred at the Serapeum. The earliest burials are found in isolated tombs, as the cult gained importance underground galleries were dug that connected subsequent burial chambers. One of the cult practices involved the dedication of commemorative stone tablets with dates relating to the life and death of the Apis.