Iry-pat

Iry-pat was an ancient Egyptian ranking title, that is a title announcing a high position in the hierarchy of the country. Iry-pat was the highest ranking title at the royal court, and only the most important officials could bear this title. It is attested as early as during the First Dynasty: one of the first confirmed holders was Merka, official under king Qa'a.
In the New Kingdom, the title was often given to the crown prince and the title announced that the holder was the next ruler of the country. It is therefore sometimes translated as Hereditary or Crown Prince. Under Tutankhamun, Horemheb was officially designated the iry-pat and successor but did not succeed the boy king, Ay intervened and seized the throne instead, keeping it for about 4 years before Horemheb assumed power as pharaoh.