In 1887 the great Anglo-American explorer Henry Stanley set out to save Emin Pasha, governor of Equatoria, from Moslem unrest. It was, in the words of the Royal Geographical Society librarian, "in some respects the most remarkable expedition that ever entered Africa." In adapting this quotation for the title of her straightforward but stirring history of that expedition (originally published in 1947), the late novelist Olivia Manning dropped the intensifying "most." No matter: As she tells it, the story speaks for itself.

To begin with, the expedition had an uncertain status. The Egyptians, who nominally controlled Equatoria, supported it. The Germans, whose fellow citizen Emin was, supported it. The British, distressed over the recent failure of their army to rescue Gen. Gordon from the calamitous siege of Khartoum, heartily supported it. But for political and financial reasons, none of their governments could sponsor it, and the mission had to be financed by private subscription.

At its head was Henry Morton Stanley, status equally iffy. An English orphan who fought in the American Civil War, he was a superlative explorer even in an age that produced talented ones in droves. Had he not, after all, tracked down Dr. Livingstone and traced the Nile to its source? And yet he had an infantile temper and a bad case of class insecurity. (He uttered that silly anticlimax, "Dr. Livingstone, I presume," because he thought it was what a proper Englishman ought to say.)

Then there was the territory they had to trek through: the sweltering, dank, Stygian jungle known today as the Ituri rain forest (of Zaire, formerly the Congo). Virtually everywhere in the world, Manning points out, humans had tampered with forests, but not here. "The trees were direct descendants of the prehistoric trees that had stood on the same spot, and they grew with the same luxuriance. Some rose to a height of 200 feet . . . Trees fell hourly with a rushing crash that shook the ground. Trunks of fallen trees were quickly bored hollow by ants and would crumble at a touch."

Trees were not the only objects that attracted the jungle's insects. "There were some beetles that burrowed beneath the skin, others that bored into the tent poles and sent clouds of sawdust into the soup, others, two and a half inches long, that blundered into the tents whenever a light was lit and bumped around until driven away. The ants got into the food and, if swallowed by accident, ate through the stomach membranes. A sleeper covered with ant-bites would awake to find himself writhing with a burning itch as though he had been flogged with nettles."

Hostile natives planted poison-tipped skewers beneath leaves in the expedition's path. All told, half of Stanley's several hundred men had died by the time he reached Emin.

At which point came the outrageous discovery that Emin Pasha -- a pseudonym that means "faithful official" -- didn't much want to be rescued. Supported and resupplied, yes, but not separated from the beloved people he governed.

Born either Jewish or Lutheran (depending on whom you read), he was a physician who had insinuated himself into the family of the Turkish governor of western Albania. Emin took up with the official's wife and, after the husband died, brought her to Germany but declined to marry her.

He disappeared, turned up in Alexandria, and made his way to Equatoria, where he so impressed Gordon that a few years afterward the latter appointed him governor of the region. But he lacked Gordon's invincible will and, in Manning's summation, "never throughout his life guarded against the possibility of his own friendliness being met with anything but equal friendliness."

When finally Stanley's force reached Emin, he showered them with gifts -- sheep, goats, a demijohn of liquor -- but "failed to notice how coldly Stanley received them." One can sympathize with both men's positions -- Stanley and his troop enduring a hellish ordeal only to find a supposed wretch comfy in largess; Emin grateful for aid, especially ammunition, but still well-ensconced as governor, thank you. (Anywhere else, Emin knew, he would be a rank nobody.) For months Emin dithered and dawdled until at length Stanley all but bodily carried him and his closest followers away.

Three years later, after a sojourn in England, Emin returned to his beloved province and was assassinated. Stanley made a book out of his nightmarish experience, "In Darkest Africa," which only enhanced his fame.

Olivia Manning, author of the Balkan and Levant trilogies, was a fine storyteller and a compassionate judge of people. "The Remarkable Expedition" is fair to both principals without slighting their bizarre cussedness by one iota.