The Nile isn't just a river in Egypt

The life-giving Nile of lower Egypt trickles first from two springs in Burundi and Rwanda and then meanders 4,238 miles as the White Nile through great equatorial lakes; loses itself in tangled and difficult swamps; tortuously emerges to run freely toward its confluence with the much more powerful, if shorter, Blue Nile from Ethiopia; and then flows over cataracts and dams through the great desert to the Mediterranean Sea.

Over five millenniums, the nutrient- and silt-laden Nile floodwaters enabled agriculture and civilization to flourish all along its lower reaches. When the annual summer flood failed, however, the northern Sudan and all of classical and modern Egypt suffered hideously.

Collins links the dark ages of dynastic Egypt and the successes of invading outsiders to those sometimes prolonged periods when the Nile withheld its renewing gift. In turn, those dry spells reflected shifts in the rainfall patterns of equatorial Africa and highland Ethiopia, not - as the Egyptians always feared - to the manipulative scheming of Ethiopian monarchs or African chieftains.

There were many efforts to measure the flows of the Nile, and then to harness it effectively. Taming the Nile, the quixotic goal of administrators from early times, led to the first small dams, and in the early 20th century to dams in the Sudan. President Gamal Abdel Nasser's Aswan High Dam of 1970, with its 300-mile lake and its ancillary dam at Roseires in the Sudan, were together intended to regulate the river forever, smoothing out the years of high and low water. But the mighty Nile refused to capitulate, and the impoundment of its waters has led to great silting and weakening of the dams, the impoverishment of Egyptian agriculture, unexpected disease, and unanticipated economic and social consternation.

Collins's seamless biography captures the soul of a river that is both a result of and a continuing influence upon Africa's geology, climate, history, peoples, economy, and politics. Collins roams over the 2 million-square-mile basin of the Nile - the smaller rivers, the large and tiny lakes, and the glacier-capped mountain ranges - and writes movingly of the glory and challenges faced by the immense cascade of water as it makes its way over myriad waterfalls and past pumping stations, villages, towns, and cities to its ultimate destination. He also captures the trials and triumphs of the Nile's sometimes human- assisted passage through the Sudd - a vast eddying swamp-like mass of lagoons and channels that long defied explorers and entrepreneurs as they attempted to follow the White Nile south into equatorial regions.

Counterintuitively, more of the merged waters of the Nile come from the Blue branch, not the much longer and more tortuous White system. The Blue starts higher than the White, at 9,000 feet, and then rushes into shallow Lake Tana. From shores ringed by Coptic Christian monasteries, the Blue carves a great arc through the lava dikes and sandstone plateaus of western Ethiopia, strengthened by three significant and many minor tributaries until it leaves the highlands and crosses into the Sudan as a source of regular refreshment.

As in any great biography, there are diversions off the main channel. Collins swoops readers into the Baro Salient, that riverine mapmaking mistake that thrusts Ethiopia into the southern Sudan, where commerce coursed clandestinely across borders. He takes us on a fascinating search for 15-foot canaries - not in John Williams' standard "Field Guide to the Birds of East Africa" - high up in the Mountains of the Moon (the Ruwenzori Range). And he supplies unexpected facts. For instance, as mighty as the Nile may be, its volume of fresh water delivered to the Mediterranean is only 2 percent of the total of the Amazon River and 15 percent of that of the Mississippi River. For much of its 160 million-year history, the Nile emptied into the Indian Ocean; only in comparatively recent geological times has it flowed north.

This is an easy book to read and to like. Yet there are occasional anachronisms, where sketches of people or places forsake the findings of modern linguistic and ethnological scholarship, and repetition of pet phrases or factoids. But the book's big flaw is the fault of the publisher: The quality and clarity of the maps and photographs are inadequate for a study as important as this panoramic biography of a pulsing river.

• Robert I. Rotberg directs Harvard's Program on Intrastate Conflict and is president of the World Peace Foundation.