More than a thousand years ago, at the edge of Western Europe, 10th century Córdoba was the capital of Islamic Iberia, the “Jewel of the World”, symbolizing cultural and intellectual efflorescence. According to historical sources, the ruins of the mythical caliphal city-palace of Madīnat al-Zahrā were located a short distance further west of La Mezquita. The raison d’être of this citadel has been investigated from a multidisciplinary approach for more than two decades. The present investigation illustrates the significance of the roles of architecture, astronomy and philosophy at a time when Caliph Abd al-Rahman III embarked on building “The Brilliant City” in 941. While the elaborate artistic programme attests to the magnificence of the architectural styles, this research considers religious and philosophical factors as the possible prime motives behind the design of the royal ceremonial spaces.