Palace P was probably not immediately finished - at least, that is the interpretation of the excavators, who arrived upon this conclusion to explain why the building was not symmetrical. Because this is very unusual, it was assumed that the palace was not completed according to the original design. The reason may be that the project was abandoned by Cyrus' son Cambyses (r.530-522); it is likely that Darius the Great (r.522-486), who built Persepolis, also made sure that the Pasargadae complex could be used. At least, he left some inscriptions

Like Palace S, Palace P has an inscription (CMa) in Old Persian cuneiform script, which mentions that this building was made by king Cyrus. Because this type of writing was designed in 521 - it was used for the first time in the Behistun Inscription, which also states that this "Aryan script" was designed especially for the purpose - the text in the Palaces P and S must have been added by Darius I the Great. Probably, this king, an usurper, tried to show continuity with the founder of the Persian Empire by stressing that they belonged to the same Achaemenid family.