So for instance, Aurelian, though acceding to the throne by usurpation, was the sole and undisputed monarch between 270 and 275, and thus was a legitimate emperor. Gallienus, though not in control of the whole Empire, and plagued by other claimants, was the legitimate heir of (the legitimate emperor) Valerian. Claudius Gothicus, though acceding illegally, and not in control of the whole Empire, was the only claimant accepted by the Senate, and thus, for his reign, was the legitimate emperor. Equally, during the Year of the Four Emperors, all claimants, though not undisputed, were at some point accepted by the Senate and are thus included; conversely, during the Year of the Five Emperors neither Pescennius Niger nor Clodius Albinus were accepted by the Senate, and are thus not included. There are a few examples where individuals were made co-emperor, but never wielded power in their own right (typically the child of an emperor); these emperors are legitimate, but are not included in regnal lists, and in this article are listed together with the senior emperor.