Botswana’s unit of currency is called the pula for a reason – in Setswana pula means rain, something that has been valued here for longer than diamonds. Built on sand, the nation’s famously inhospitable Kalahari is actually seasonal, with much life being precariously sustained by the hot summer’s cloudbursts. In the early winter of 1850 it was the remaining moisture from those rains that lingered in waterholes and managed to sustain an expedition crossing ‘the great thirstland’. Today, the cool, dry winters are still the best time to venture across the desert, though with a Land Rover replacing ox wagons it takes days instead of months.

“It hasn’t rained like this in June since 1994,” reveals Keith Rampton of Explorer Safaris as we arrive at Kolobeng, the melancholy remnants of a famous mission some 20km south of Gabarone. These downward torrents, caused by a maverick weather system that has migrated from the distant Atlantic, keep us company as we follow a route twice endured – in conditions of much greater hardship – by David Livingstone, his infant children and his perennially pregnant wife. While the Livingstones almost died of thirst, we merely get wet.

Livingstone, with gentleman-adventurers William Cotton Oswell and Mungo Murray, had already made the 960km journey northwest from Kolobeng to Lake Ngami in the winter of 1849, and had received the Gold Medal of the Royal Geographical Society as a result. This marked the start of his career as an explorer, although Ngami, which is fed by rivers debouching from the Okavango Delta, was already known to European traders and hunters, not to mention the BaTawana people who lived on its shores.

No sooner had he reached the lake, the restless missionary felt himself on the brink of greater, wilder adventures. Beyond Ngami, he was told, in the land of the Makololo, were mightier waterways. A vision of ‘God’s Highway’ – a conduit to bring Christianity and commerce into the heart of Africa and undermine the slave trade – began to germinate. But there were several impediments to Livingstone’s growing obsession with exploration: his wife and children.

Mary Moffat Livingstone was the eldest daughter of Robert Moffat, the charismatic missionary who translated the Bible into Setswana and founded the successful mission at Kuraman in the Northern Cape, which still flourishes today.  She was born in the bush at nearby Griquatown, spoke Setswana as fluently as English and was trained by her accomplished mother in the skills required for mission life. She was thus perfectly equipped to partner the young Scot whom she met and married at Kuraman in 1845. However, her honeymoon – a 12-day journey by ox wagon to Livingstone’s first mission at Mabotsa – was an emblem of things to come: a nomadic life often fearful and lonely and, in its middle years, downright wretched.

The forlorn foundations of the mission house and church at Kolobeng, with the barely marked grave of her fourth child, Elizabeth, are relics of the only settled home of Mary’s marriage. For when Livingstone quarrelled with his colleague at Mabotsa and failed to establish another mission at Chonuane (both sites now marked by the Historical Monuments Commission of South Africa), the family moved to the banks of the Kolobeng River. Their five years there with the Bakwain and their  chief, Sechele, were interrupted by Livingstone’s three expeditions to the interior, two of which involved the whole family.

Kolobeng was threatened by Boers and disabled by drought when Livingstone planned his second excursion, and this time Mary refused to be left behind. Their children, Robert, Agnes and Thomas, were (respectively) four, three and one years old, and she was again pregnant. Yet the lurching discomfort of travel by ox wagon and the monotony of the desolate flatlands were minor obstacles compared with the ordeal of the return journey, and later Livingstone recorded: “We were happy as a family.” When they reached the mature woodland of the Boteti River and then the shores of Ngami, the atmosphere became almost festive as the children splashed in the shallows.

Livingstone wanted to press on to the Makololo capital, but when Agnes and Thomas became gravely ill with malaria they began the long trek back to Kolobeng. Elizabeth – “a very lively young lady”, according to her father – was born almost as soon as they were home. Mary suffered a stroke shorly after giving birth, and her new daughter caught pneumonia. The mother recovered, but her baby died. Livingstone seemed to make no connection between these tragedies and the previous months of gruelling desert travel.

Today all that remains of Elizabeth’s grave in Kolobeng is a circle of stones in an unkempt grove of trees. Despite this terrible loss, the family made an even longer journey to the north the following year, and finally reached the Chobe – again with the generous support of William Cotton Oswell, who admired not only Livingstone but his stoical wife. As usual, Mary was pregnant. “I must again wend my weary way into the far interior,” she wrote to her mother, “perhaps to be confined in the field.”

She was. Her fifth child, named Oswell after their benefactor, was born on the banks of the Boteti River, but not before the entire party had almost perished in the barren Mababe Depression, now part of Chobe National Park. It was only the superior sense of the oxen that had saved them. As the dehydrated children cried and weakened, the oxen were turned loose and had happened to sniff out a trickle of foul-smelling water slimy with rhino dung.

To subscribe or buy back issues, click here 

Once again Livingstone had jeopardised his family, and yet he realised that his loved ones were hampering “God’s work” – his compulsive drive to penetrate uncharted Africa. He had to choose between them. Mary and the children were dispatched to the United Kingdom, where she led a miserable, cash-strapped, peripatetic life until Livingstone returned from his exploration of the Zambezi and coast-to-coast journey four years later.

Today it’s possible to trace the general route of the Lake Ngami expeditions on tar or gravel roads, taking in some of the Livingstone highlights. With the assistance of a map sketched by Oswell and the air-conditioned comfort of Keith’s Land Rover Discovery, we skirt the edge of the Makgadikgadi Pans (where the rain finally stops) and pause to inspect Chapman’s Baobab, where the expeditions camped. When we reach the Boteti River, now flowing again after years of neglect by the fickle waters of the Okavango Delta, I’m startled by the sudden transition from the harsh landscape of the Kalahari to the river’s verdant conduit.

“If I had to be confined in the field,” I remark, “this is the spot I’d choose.”

We’re now within striking distance of Lake Ngami, which these days can be a disappointing pond, slimy with cattle dung, or a brilliant expanse of blue water patrolled by spectacular water birds. We don’t know what we’re going to find  until we reach Maun, as the lake’s plenitude depends on the water levels of the delta. The communal farmland of the original basin indicates just how much the lake has shrunk since Livingstone’s day. What remains still takes some finding, with no height on the flat scrubland to give any kind of view beyond the natural barricades of tall, prickly burrs.

Even with the help of Keith’s GPS and advice from the Maun locals, we make little sense of the tangled cattle tracks, and find only puddles. Then we pick up a hitchhiker: a village ancient returning from his cattle post. “Ngami” is the only word we have in common, and when we drop him off near his home he waves us down yet another cattle track between yet more stands of burrs. And suddenly there it is – a sheet of blinding beauty in the low sun, with a fish eagle perched on a solitary rock, a pair of pelicans on the far bank and a flypast of Egyptian geese to celebrate our arrival.

The water systems of the delta have worked their magic. Keith and I toast their alchemy, then reflect a little sadly on the lake’s ghosts of the past: Robert and Agnes paddling; Mary seated on a log, enjoying a rare, frivolous moment of family life; and the toddler Thomas clinging to her long skirts. Livingstone, we fancy, has his back to the lake, his gaze already fixed on the more remote waters of the Zambezi and the enigmatic landmass between the Atlantic and Indian oceans.

*  Julie Davidson would like to thank Keith Rampton and Explorer Safaris (www.explorersafaris.co.za) for their help in South Africa and Botswana. Their David Livingstone ‘The Missionary Years’ Cultural Safari includes: Kuraman, Mabotsa and Chonuane in South Africa; Kolobeng, Makgadikgadi, the Boteti River, Lake Ngami and the Chobe River in Botswana; Linyanti in Namibia’s Caprivi Strip; and the Zambezi and Victoria Falls in Zambia.