Explanation: Al-Andalus is the term for the Muslim-ruled portion of the Iberian peninsula. For much of the medieval period, it was a prosperous, relatively tolerant, and complex society, with advanced organizational structures and techniques that the rest of Europe would struggle to catch up with. Most notably, medical and medicinal texts which would become foundational for medicine even in Christian Europe, irrigation and water systems of a type and scale that had not been seen since the fall of the Roman Empire, early rationalized attempts at examining agriculture (and the creation and spread of agricultural techniques from Al-Andalus springing from those early examinations), and public services (including street lighting ordnances, policing, sanitation, and roadwork).

Unfortunately, Al-Andalus came to an end by the resurgence of Christian Spain and Portugal, which, over several hundred years, chipped away at, and then eradicated completely, the Muslim presence in the Iberian peninsula. Al-Andalus was heavily splintered politically between what were effectively relatively equal city-states and principalities, who all hated each other more than they hated the Christian Crusaders, whereas Christian Spain and Portugal were split into maybe 3-4 realms at any given time, and with each of a size significant enough to enforce hegemony over any minor players.

Divided we fall…