Younger brother of Takelot I, on any inscriptions found dating to Iuwelot at Thebes, there are curiously lacking the name of the King Takelot I. For example three graffiti (Nile-level) from Karnak record the various Years but not the king.
Another example of the lack of Takelot's name comes from a granite stela of Iuwelot in which he lists his 'will'. In the stela he leaves all his properties to his son Khamweset (from his wife - Tadenitenbast - the royal granddaughter). There is no mention of Takelot I, Iuwelot refers only to his father, Osorkon I. The stela also details the northward limit of Iuwelot's rule as military commander of the south ('to the province of Siut' - Middle Egypt).
Iuwelot also had a daughter - Djedeseesankh, who married a priest who became a 3rd prophet of Amun.