Reign

Psusennes I's precise reign length is unknown because different copies of Manetho's records credit him with a reign of either 41 or 46 Years. Some Egyptologists have proposed raising the 41 year figure by a decade to 51 years to more closely match certain anonymous Year 48 and Year 49 dates in Upper Egypt. However, the German Egyptologist Karl Jansen-Winkeln has suggested that all these dates should be attributed to the serving High Priest of Amun, Menkheperra instead who is explicitly documented in a Year 48 record.^[12] Jansen-Winkeln notes that "in the first half of Dyn. 21, [the] HP Herihor, Pinedjem I and Menkheperra have royal attributes and [royal] titles to differing extents" whereas the first three Tanite kings (Smendes aka: Nesubanebded, Amenemnisu and Psusennes I) are almost never referred to by name in Upper Egypt with the exception of one graffito and rock stela for Smendes.^[13] In contrast, the name of Psusennes I's Dynasty 21 successors such as Amenemope, Osochor, and Siamun appear frequently in various documents from Upper Egypt while the Theban High Priest Pinedjem II who was a contemporary of the latter three kings never adopted any royal attributes or titles in his career.^[14]

Hence, two separate Year 49 dates from Thebes and Kom Ombo^[15] could be attributed to the ruling High Priest Menkheperra in Thebes instead of Psusennes I but this remains uncertain. Psusennes I's reign has been estimated at 46 years by the editors of the Handbook to Ancient Egyptian Chronology.^[16] Psusennes I must have enjoyed cordial relations with the serving High Priests of Amun in Thebes during his long reign since the High Priest Smendes II donated several grave goods to this king which was found in Psusennes II's tomb.

During his long reign, Psusennes built the enclosure walls and the central part of the Great Temple at Tanis which was dedicated to the triad of Amun,Mut and Khonsu.^[17]