The town of Agadez, today in central Niger, was from the 15th century a crossroads for pastoralists, caravaneers and artisans. From the north came Tuaregs and Berbers; from the east, Arabs; from the south and west came Hausa, Songhai and Fulani. Security for trade and passage lay with the elected Sultan of Aïr, named for the highlands to the north. Today, the 126th sultan is an honorary official who still adjudicates affairs in a city that remains an ethnic crossroads.

The legacy of the Mongols is far from being entirely apocalyptic. In addition to the hemispheric Silk Roads trade made possible by stable Mongol rule, some of the finest arts and architecture of the Middle Ages flourished when Persian, Turkic, Arab and Chinese styles met under the Mongol ilkhans, who embraced Islam and patronized the arts from present-day Iran.

Minted first in the Habsburg capital of Vienna, the silver Maria Theresa thaler—the word rhymes with "dollar" and is the origin of the modern American term—was one of the world's most widely used currencies in the late 18th and much of the 19th century. It could be found from the Americas to China, often adapted, and sometimes counterfeited. One of the places it was hugely popular was the Arabian Peninsula, where its reliably high silver content made it valuable both for commerce and for silversmithing.