What have we learnt about the Nile since the mid-1970s, the moment when Julian Rzóska decided that the time had come to publish a comprehensive volume about the biology, and the geological and cultural history of that great river? And what changes have meanwhile occurred in the basin? The human popu- tion has more than doubled, especially in Egypt, but also in East Africa. Locally, industrial development has taken place, and the Aswan High Dam was clearly not the last major infrastructure work that was carried out. More dams have been built, and some water diversions, like the Toshka lakes, have created new expanses of water in the middle of the Sahara desert. What are the effects of all this on the ec- ogy and economy of the Basin? That is what the present book sets out to explore, 33 years after the publi- tion of "The Nile: Biology of an Ancient River". Thirty-seven authors have taken up the challenge, and have written the "new" book. They come from 13 different countries, and 15 among them represent the largest Nilotic states (Egypt, Sudan, Ethiopia, Uganda, and Kenya). Julian Rzóska died in 1984, and most of the - authors of his book have now either disappeared or retired from research. Only Jack Talling and Samir Ghabbour were still available to participate again.