‘On est déjà en retard, Monsieur Nicolas.’

I was hung over. I was tired. I was being told off by a retired colonel. This wasn’t a good start to the day.

‘Je suis désolé, Monsieur Antoine,’ I replied dutifully, getting into the Toyota Landcruiser beside him.

We left Bujumbura’s Hôtel de l’Amitié and set out into a muggy and overcast morning. The grey-blue expanse of Lake Tanganyika was visible to our west, flanked on the opposite shore by the buttresses and ridges of the Mitumba mountains in the Congo. To our east, the land rose precipitously into the first line of Burundi’s milles collines. Around us, plain white buildings hand-painted with brightly-coloured advertisements were interspersed with 1930s art deco.

It was my umpteenth visit to Burundi in recent months on behalf of donors or aid agencies. Notwithstanding the slow pace of progress, I had come to appreciate the tranquillity of this little nook in the heart of Africa. But rather than visiting the usual catalogue of ministries and development officials, my intention this time was to travel to the southernmost source of the Nile, in the south-easterly reaches of the country.

My hope to see the source of this great watercourse emerged from romantic notions of the significance of such a beginning. My companion, Colonel Ngurazizi was a well-educated product of the army that had, until the last decade, held sway over the twists and turns of Burundi’s 20^th century history. He was a gentle, fatherly man in late middle age, and as we drove through the country’s interlocking hills and valleys he told me about his childhood village in the south, and about his children, spread all over the globe in Kenya, China and the USA. ‘There’s not much for them in Burundi, but at least they have married Burundians.’

He’d been to the source a couple of times when his children were young but was evasive – a pronounced national trait – about what significance it held for the country. ‘We appreciate the custom it brings,’ was all he would say.

For centuries, locating the source of the Nile had been an obsession for explorers and scholars. Herodotus chronicled his passage up the river to modern-day Aswan, considered by the ancient Egyptians to be the Nile’s place of origin. Ptolemy posited that it rose in the Mountains of the Moon, which straddle the Ugandan and Congolese border, while the Ottomans traced the river as far as Juba in South Sudan. When John Hanning Speke and, later Henry Morton Stanley, ‘discovered’ Lake Victoria in the early 1870s, they were convinced that they had also discovered the Nile’s source. But they too were wrong, after all their efforts. I was off to the real source on a day trip in a 4×4, and I felt like a bit of a fraud.

We were leaving the hills and emerging into a flatter landscape. A verdant plain dotted with hillocks and copses stretched to the horizon. The colonel pulled up the vehicle. On this plain, he pointed out, were the houses of three of the country’s recent presidents. ‘Armed with telescopes they could have waved at each other from their verandas!’ It could have been something in a Wes Anderson film.

He explained that Presidents Micombero, Bagaza and Buyoya were all members of an influential sub-group of the Tutsi, and that they had shaped Burundi’s turbulent path with their coups, efforts at development and divisive policies. On their watch, the country had gradually descended into ethnic turmoil and civil war, culminating in two decades known as la crise, which ended in 2006. ‘Burundi’s heyday was in the ’60s and ’70s but la crise put a stop to it all. For obvious reasons tourists stopped coming and people started leaving.’

A light drizzle began to fall and I allowed the colonel’s reminiscences of lakeside weekends and happier times in the officers’ mess to fade into the background. The radio was churning out a mixture of Congolese rhumba and bad European dance music. Every few miles, a startling collage of colour leapt out of the green and grey; the dresses of women at market. Eventually a battered and rusty sign appeared around a bend: Bienvenue à la source du Nil.

We parked, paid the fee to the attendant warden and were pointed up a hill. At the top was a stone pyramid the height of a man, and a plaque in Latin commemorating the southernmost source’s discovery – Dr. Burkhardt Waldecker, 1938 – as well as all the men that had come before and the many names the Nile adopts on its way to the sea.

A drop of water falling on the surrounding hills might have a long journey ahead of it. After some time in brooks and streams, it would find itself in the Ruvubu in Rwanda, over which German and Belgian occupying forces marched at the turn of the 20th century – movements echoed more recently by the exodus of refugees fleeing the Rwandan genocide. Proceeding through the lush landscape of Uganda’s great lakes, drifting and racing through the Victoria and Albert Nile, it would then flow into the world’s newest state: troubled South Sudan. From there to Juba, through the papyrus swamp of the Sudd and, passing a climax of British-French imperial rivalry at Fashoda, into the evocatively named Lake No.

There it would finally become part of the majestic White Nile, soon to meet its mountain-reared, Ethiopian twin in Khartoum. It would pass the tombs and temples of kings and the pyramids of pharaonic Egypt. It would cascade through the Aswan Dam and give sustenance to the world’s oldest agricultural land. Finally, it would meet its salty end at Alexandria, dispersing into the Mediterranean.

‘In Burundi we believe this is the real source of the Nile. Uganda, Ethiopia – their sources are really just tributaries,’ said the colonel.

Then it was down to the spring itself, in a grove below. We walked down a wet and woody path through the trees, turned a corner, and there it was: a block of concrete set into the side of the hill, with a small, grey plastic tube protruding. Out of this came a slow trickle of water. The entire assembly was surrounded by brown stone rubble and the flow disappeared into a dank bed of moss almost as soon as it dribbled forth.

From small beginnings come great things or, if you will, the Nile comes out of a pipe.