F. Miranda notes that this surname, together with its variants, derives from names of Germanic origin of Frankish tradition: Altiero, Autiero, Ottiero, formed from the fusion of the terms alda ("old, wise") or audha ("power, wealth") with haria ("army"). He documents the personal name Auterius in Genoa from the 12th century, and records early traces of its transformation into a surname at the beginning of the 14th century, with Petrus Auterii, a figure of the Cathar movement.

V. Blunda agrees on the Germanic origin, but specifies the compound as Aud Harj, with the sense of "prosperous army" or "rich host", formed from aud ("prosperity, wealth") and harj ("army, armed host"). Blunda links this combination with the Lombard ideal of the Germanic comitatus, a practice by which the loyalty of the warriors was secured through material gifts from the lord.

As for its geographical distribution, Miranda characterises it as a surname peculiar to eastern Sicily, concentrated mainly in the Catania area —Palagonia, Paternò, San Giovanni La Punta— and in the Syracuse area —Solarino, Floridia—, with minor specific clusters in the areas of Palermo, Trapani and the Enna area. Miranda also notes presence in Lombardy, Liguria, Piedmont, Calabria and Tuscany.