In 711 a force crossing from North Africa under Tariq ibn Ziyad defeated the Visigothic king Roderic, and within a decade most of the Iberian peninsula was under Umayyad rule. Conquest was accomplished as much by treaty as by battle: local lords who submitted kept their lands and their subjects kept their religion under tribute, as the surviving Pact of Tudmir shows. Arab and, in far greater numbers, Berber groups settled across the peninsula in a hierarchy that placed Arabs above Berbers above native converts, and the resulting tensions produced the Berber revolt of 740. Native Christians and Jews continued under dhimmi status, and conversion to Islam proceeded gradually over more than two centuries rather than as an immediate consequence of conquest. There is no evidence of mass expulsion of the indigenous population; the measurable displacement is the movement of some Christians into the northern mountains, which cannot be quantified.
An Umayyad army of largely Berber troops under Tariq ibn Ziyad, followed by Musa ibn Nusayr, destroyed the Visigothic kingdom and settled Arab and Berber groups across the peninsula under a tributary regime for Christians and Jews
There is no census. McEvedy and Jones's Atlas of World Population History puts Iberia at about 4 million around 700, back-projected from later Islamic fiscal records and Christian land surveys; other reconstructions run from 3 to 6 million. The number of Arab and Berber settlers is separately estimated at only tens of thousands.
No usable figures. The conquest turned on a small number of engagements and many negotiated surrenders; neither the Arabic chronicles nor the Latin Chronicle of 754 supplies casualty totals, and no modern reconstruction attempts one.
Spain, Morocco