The word Lombardy comes from Lombard, which in turn is derived from Late Latin Longobardus, Langobardus ("a Lombard"), derived from the Proto-Germanic elements *langaz + *bardaz; equivalent to long beard. Some sources derive the second element instead from Proto-Germanic *bardǭ, *barduz ("axe"), related to German Barte ("axe").
During the early Middle Ages "Lombardy" referred to the Kingdom of the Lombards (Latin: Regnum Langobardorum), a kingdom ruled by the Germanic Lombards who had controlled most of Italy since their invasion of Byzantine Italy in 568. As such "Lombardy" and "Italy" were almost interchangeable; by the mid-8th century the Lombards ruled everywhere except the Papal possessions around Rome (roughly modern Lazio and northern Umbria), Venice and some Byzantine possessions in the south (southern Apulia and Calabria; some coastal settlements including Amalfi, Gaeta, Naples and Sorrento; Sicily and Sardinia). The Kingdom was divided between Longobardia Major in the north and Langobardia Minor in the south, which were until the 8th century separated by the Byzantine Exarchate of Ravenna (roughly Romagna and northern Marche, and initially also Emilia and Liguria) and the Papacy (which was initially part of the Exarchate). During the late Middle Ages, after the fall of the northern part of the Kingdom to Charlemagne, the term shifted to mean Northern Italy. (See: Kingdom of Italy (Holy Roman Empire)). The term was also used until around 965 in the form Λογγοβαρδία (Longobardia) as the name for the territory roughly covering modern Apulia which the Byzantines had recovered from the Lombard rump Duchy of Benevento.