Numidia was the ancient kingdom of the Numidians in northwest Africa, initially comprising the territory that now makes up Algeria, but later expanding across what is today known as Tunisia and Libya. The polity was originally divided between the Massylii in the east and the Masaesyli in the west. During the Second Punic War, Masinissa, king of the Massylii, defeated Syphax of the Masaesyli to unify Numidia into the first Berber state in present-day Algeria. The kingdom began as a sovereign state and later alternated between being a Roman province and a Roman client state.

The Numidians were the Berber population of Numidia. The Numidians were originally a semi-nomadic people, they migrated frequently as nomads usually do but during certain seasons of the year, they would return to the same camp. The Numidians soon became more than pastoralists and started to engage in more urban professions. The Numidians were one of the earliest Berber tribes to trade with Carthaginian settlers. As Carthage grew, the relationship with the Numidians blossomed. Carthage's military used the Numidian cavalry as mercenaries. Numidia provided some of the highest quality cavalry of the Second Punic War, and the Numidian cavalry played a key role in several battles, both early on in support of Hannibal and later in the war after switching allegiance to the Roman Republic. Numidian culture flourished between the end of the Second Punic War and around the Roman conquest, with Massinissa as the first king of a unified Numidia.