Centuries before oil became the currency of power in West Asia and post-Ottoman Arab fraternity its lever, another commodity earned the region fortune and fame in equal measure. Its importance originated in the pagan religious rituals of biblical times and rose to a peak in the Christian era. In the pre-Islamic cartographic annals of Claudius Ptolemy, the 1st century CE polymath of Alexandria whose mastery over geography and astronomy guided expeditions of exploration and trade into the land that he described as Arabia Felix (Happy Arabia), it blazed a fragrant trail from the Horn of Africa to Babylon, Mesopotamia and Rome.