From A Labyrinth of Kingdoms: 10,000 Miles through Islamic Africa, by Steve Kemper (W. W. Norton, 2012), Kindle pp. 175-177:
THE OFFICIAL REASON FOR THE MILITARY EXPEDITION WAS TO PUNISH the vassal state of Mandara for disobedience. The real reason was that the “coffers and slave-rooms of the great men” of Bornu were empty. The lawless Welad Sliman and the legitimate government of Bornu were both motivated by greed, but the mercenary Arabs didn’t bother to disguise or rationalize their conduct.
A Bornu military campaign moved with ponderous, gaudy pomp. The boom of a great drum signaled the break of camp. Twenty thousand men set off to the drum’s deep cadence, along with 10,000 horses and 10,000 beasts of burden. Barth described the scene:
. . . the heavy cavalry, clad in thick wadded clothing, others in their coats of mail, with their tin helmets glittering in the sun, and mounted on heavy chargers . . . the light Shuwa horsemen, clad only in a loose shirt and mounted upon their weak, unseemly nags; the self-conceited slaves, decked out gaudily in red bernuses or silken dresses of various colors; the Kanembu spearmen, almost naked, with their large wooden shields, their half-torn aprons round their loins, their barbarous head-dresses, and their bundles of spears; then, in the distance behind, the continuous train of camels and pack-oxen. . . .
The pack animals were burdened with “tents, furniture, and provisions and mounted by the wives and concubines of the different chiefs, well dressed and veiled.” The vizier and the sheikh each brought “a moderate number” of concubines—eight for Haj Beshir, twelve for Umar, all dressed in white burnooses. Four fan-bearers in multicolored attire followed the sheikh, as did shrill musicians. Everyone, wrote Barth, was “full of spirits, and in the expectation of rich booty, pressing onward to the unknown regions toward the southeast.”
The army moved over the countryside like locusts. The courtiers brought their own provisions, but the soldiers were expected to supply themselves and their horses from the fields and livestock they passed. “To the ruin of the country,” noted Barth. Cornfields were stripped, livestock seized.
He and Overweg had neither provisions nor money to buy any, but the sheikh and the vizier kept them well fed, at first: rice boiled with milk, bread and honey, sheep and sorghum. The Germans spent most evenings in intellectual tête-à-tête with the vizier, whose curiosity matched theirs. Haj Beshir’s travels to Egypt and Mecca had enlarged his perspective and excited his interest in foreign matters. “Our conversation at some of these African soirées with the vizier,” wrote Barth, “became sometimes so learned that even Ptolemy with his ‘Mandros oros’ was quoted.” On another evening, “a disputation arose of so scientific a character that it might have silenced all those who scoff at the uncivilized state of the population of these regions.”
They often discussed slavery. Barth urged Haj Beshir to abolish it in favor of agriculture, industry, and trade. The vizier agreed that slave-hunting was a sordid business, but no other commodity paid as well, and Bornu needed the money for European firearms to protect itself against enemies—firearms that were also used, noted Barth, to hunt down and enslave or massacre yet more people. The high profits from slavery also led to a taste for luxuries that could only be sustained by capturing and selling more slaves. “Such is the history of civilization!” wrote Barth acerbically. He concluded that European nations were hypocritical for condemning the slave trade while profiting from the gun trade that fueled it. The vizier offered to end slave-trading in Bornu—though not domestic slavery—if the British government would send Bornu 1,000 muskets and four cannons.
Haj Beshir was one of the two great friends Barth made on his journey (the other was Sidi Ahmed al-Bakkay, the sheikh of Timbuktu). “I repeat that, altogether, he was a most excellent, kind, liberal, and just man,” wrote Barth of Haj Beshir, “and might have done much good to the country if he had been less selfish and more active.”