[1] It is often united with the sea eagles, buteos, and other more heavyset Accipitridae, but more recently they appear to be less distinct from the slenderer accipitrine hawks than previously believed.

[2][3] Aquila belongs to a close-knit group of "typical" eagles including genera Hieraaetus, Lophaetus, Ictinaetus and Clanga.

Between 2005 and 2014, the British Ornithologists' Union included both Bonelli's and the booted eagle in Aquila.

(p.) hastata) are thought to be genetically closer to Ictinaetus and Lophoaetus than to other Aquila species, and may be placed into a separate genus, Clanga.

[19][20] Many have been moved to other genera, but several appear to be correctly assigned to this genus: Whether "Hieraaetus" edwardsi (Middle -?

Late Miocene of SW Europe) belongs into Aquila or the hawk-eagles (if the latter are indeed distinct) is unclear.