From A Labyrinth of Kingdoms: 10,000 Miles through Islamic Africa, by Steve Kemper (W. W. Norton, 2012), Kindle pp. 92-94:
In the fourteenth century the restless Moroccan traveler Ibn Battuta called Agadez “the largest, handsomest, and strongest of all the cities in Negroland.” In Battuta’s day 30,000 people lived there. It flourished as a caravan crossroads, where the Sahara met the Sahel, a band of semiarid land 300 to 600 miles wide that stretches for 2,600 miles along the Sahara’s southern edge and buffers the desert from green Africa. “Sahel” came from an Arabic word for shore or coastline. The sea was the Sahara. When travelers from the north reached the Sahel after crossing the desert, they felt the relief of stepping ashore after a long sea passage. Travelers heading north from the Sahel felt that they were casting off. Agadez, like Timbuktu, was a desert port town.
By the time Barth got there , the population had shrunk to about 7,000, but Agadez still fascinated him. The new sultan, who was about to be officially installed, received him hospitably. They conversed in Hausa, which Barth had learned during the traverse of Aïr. The sultan had never heard of the English nation, but was pleased to learn how the famous “English” gunpowder had gotten its name. That evening, he sent Barth a dish called finkaso, a thick pancake made of wheat flour, covered with butter. After the deprivations of Aïr, it tasted like “the greatest luxury in the world.” Thanks to the sultan, who sent Barth two meals every day, the explorer ate very well during his three-week stay—lamb, dates, melons, cucumbers, grains. The sultan sidestepped Barth’s invitation to sign a commercial treaty with Britain, but did write letters of passage for him to the governors of Kano and Katsina, “in rather incorrect Arabic,” sniffed the German pedant.
Barth saw slave caravans, and a salt caravan headed east to Bilma that was said to have 10,000 camels. The men of Agadez carried bows and arrows instead of spears, and rode horses instead of camels—signs of the Sahel. The busy market offered further signs: meat, millet, wheat, dates, wine, melons, and other vegetables. Women sold beads, necklaces, and finely-worked leather boxes for tobacco and perfume. Like most port towns, Agadez had a mongrel population that reflected all the peoples who passed through it, beginning with the Berber tribes that had founded it. There were Tuaregs, Hausas, Fulanis, Tebus, Kanuris, and Arabs. And also, Barth was puzzled to find, Songhais, a black ethnic group based 600 harsh miles to the west. All this diversity made Agadez a polyglot town where interpreters did good business.
But Agadez also had its own unique language, Emgedesi, spoken nowhere else in the region. To a linguist such as Barth, this was a mystery to pursue. He detected the influences of Hausa, Tamasheq, and Songhai in Emgedesi, but remained puzzled about the dialect’s origins and exclusivity to Agadez. Then came the clue that connected the dots: several Tuaregs who had been to Timbuktu told him that Emgedesi was also spoken there, 800 miles west. Barth was surprised, then thrilled as he realized the implications.
Songhai had been the most extensive empire in Central Africa’s history, greater than Mali or Ghana. It had covered portions of present-day Mali, Burkina Faso, Guinea, Senegal, and Niger. Songhai had conquered Timbuktu, another Sahelian port city of Tuaregs and Arabs. The language of the conquerors mixed with Timbuktu’s other tongues, creating a distinctive language unique to the town.
Then early in the sixteenth century, Askia, Songhai’s king, decided to extend his realm to the east, into central Sudan and Hausaland, and to curb the pesky Tuaregs to the north. He conquered Agadez in 1515 and left an occupying force there before proceeding on a haj through Egypt to Mecca, scattering legendary amounts of gold in his wake.
By the end of the sixteenth century the empire of Songhai had disintegrated. But in Agadez the descendants of the occupying army had melded with the local population. So had their language, and the resulting hybrid dialect evolved along similar linguistic lines as the hybrid language of Timbuktu, like related bird species on separate islands. This link, wrote Barth, “throws a new light over the history and ethnography of this part of the world,” and is “of the highest importance for the whole ethnography of North Africa.” It also gave him his first whiff of the fabled city of Timbuktu, a place he never expected to see.