Three of Europe's greatest rivers begin in the same geological cradle: one fertile patch of high Alpine ice in the jagged heights of central Switzerland. The consequences of this small fact can hardly be overstated: taken together, the Rhine, the Rhone and the Po do not simply symbolise three different cultures of Europe - French, German and Italian - they were the dynamo that gave them life.
Between them these extraordinary waterways have not only shaped the landscape, carving out the valleys in which early humans settled, they influenced the structure of Europe's societies - the pattern of its towns and cities, roads and railways. They laid the foundation for its economies, creating an intricate network of agriculture and trade. And they enriched its cultural diversity: language, religion, philosophy, science, politics and art - from the Romanesque buttresses and vines of Provence and the Wagnerian music of the Rhine to the spiritual and artistic miracles of Lombardy. The heart of Western European civilisation has been nourished by these waters.
But while their importance is by no means diminished today, their source is. The glaciers that have filled Europe's Alpine water tank for so long are vanishing - fast. This is a catastrophic change, and the implication is clear: we can no longer take Europe's great triumvirate of rivers for granted.
Three Rivers explores the dramatic mountain landscape where this story begins, telling the story of the glaciers themselves while also meditating on the enormous cultural consequences that have (quite literally) flowed from their cold and fragile presence - and how momentous would be their loss.
