Osorkon the Elder was the son of Shoshenq A, the Great Chief of the Ma by the latter's wife Mehtenweshkhet A who is given the prestigious title of 'King's Mother' in a document.

His existence was doubted by most scholars until Eric Young established in 1963 that the induction of a temple priest named Nespaneferhor in Year 2 I Shemu day 20 under a certain king named Aakheperre Setepenre—in fragment 3B, line 1-3 of the Karnak Priest Annals —occurred one generation prior to the induction of Hori, Nespaneferhor's son, in Year 17 of Siamun, which is also recorded in the same annals.

In 1999, Chris Bennett made a case for a Queen Karimala known from an inscription in the temple of Semna being his daughter.

Based on a calculation of the aforementioned Year 2 lunar date of this king – which Rolf Krauss in an astronomical calculation has shown to correspond to 990 BC – Osorkon the Elder must have become king two years before the induction of Nespaneferhor in 992 BC.

He is credited with a reign of six years in Manetho's Aegyptiaca and was succeeded in power by Siamun, who was either Osorkon's son or an unrelated native Egyptian.