Final answer:
The Basques did not invade, inhabit, or influence Portugal prior to the 15th century; while other groups like the Moors, Visigoths, Phoenicians, Greeks, Celts, Jews, and Romans had a notable presence and impact in the region.
Step-by-step explanation:
The group that did NOT invade, inhabit, or influence Portugal prior to the 15th century is the Basques. While the Moors, Visigoths, Phoenicians, Greeks, Celts, Jews, Romans, and others left their mark on the historical and cultural landscape of Portugal, the Basques did not have a significant presence in this region during that period.
The Phoenicians were one of the earliest known foreign influences in Portugal, establishing trade routes along the coast. The Celts inhabited parts of Portugal before the Roman conquest. The Romans themselves significantly impacted Portugal's culture and infrastructure during their extensive rule over the region. Following the decline of Roman influence, the Visigoths occupied the Iberian Peninsula. The Moors, or Muslims from North Africa, later conquered much of the Iberian Peninsula, leaving a lasting influence on the language, architecture, and customs of the region. The Jews had a historical presence in Portugal, notably before the expulsion and forced conversion policies in the late 15th century. Greeks had also established colonies, which facilitated cross-cultural exchanges.
On the contrary, the Basques, known for their unique culture and language, primarily resided in the area that is now northern Spain and southwestern France and did not exert direct influence over the territory that became Portugal.