↑ The year 2247 BC is a conservative lower estimate based on the number of cattle counts (thirty-one) that occurred during the pharaoh's reign, if counts are assumed to have been taken annually. Though Egyptian cattle counts are most often thought to have taken place biennially, late Old Kingdom reigns might have been an exception to the rule.[4] If they indeed were taken every two years, then the pharaoh reigned for about 62 years, till around 2212 BC. Pepi II is often mentioned as the longest reigning monarch in History based on accounts from the late 2nd millennium BCTurin canon and the 3rd century BC history of Egypt by Manetho. Earlier sources upon which Manetho's estimate and the Turin canon are based are lost.
