Why Malawi wraps a lake

A country along the Rift Valley

Malawi occupies a narrow, curving strip of land along the East African Rift Valley. It stretches about 840 km from north to south and is between 10 and 160 km wide.^[1] The Rift Valley runs the whole length of the country and holds Lake Malawi in the north and centre and the Shire River valley in the south.^[1]

The lake, called Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is about 584 km long and 16–80 km wide.^[2] It makes up more than one-fifth of Malawi’s area.^[1] Its only outlet is the Shire River, which joins the Zambezi in Mozambique.^[2][1] The Shire valley runs some 400 km from the lake’s southern end at Mangochi to Nsanje on the Mozambique border.^[1]

The western border mostly follows a drainage divide, the high ground where rivers stop flowing east into the lake and start flowing west to the Zambezi.^[5] So Malawi is, roughly, the lake, a band of land on its western side, and the valley of the river that drains it.^[5][1]

Livingstone and the Scottish missions

The British explorer and missionary David Livingstone reached the lake from the south in 1859, and mission work supported by British churches began in the lake area two years later.^[2][4] More Scottish missionaries came after Livingstone’s death in 1873.^[6]

The Free Church of Scotland and the Church of Scotland each planned a mission in his memory. The Free Church’s Livingstonia Mission sent its pioneer party in 1875, first to Cape Maclear at the south end of the lake.^[7] The Church of Scotland founded Blantyre, in the Shire Highlands, in 1876 and named it after Livingstone’s birthplace in Scotland.^[8] In 1878 Scottish merchants set up the African Lakes Corporation to trade in the area, with its base at Blantyre, and in 1883 Britain appointed a consul for the districts around the lake.^[4][8]

The Church of England’s Universities’ Mission to Central Africa set up a station on Likoma Island, near the lake’s eastern shore, in 1885.^[9]

Britain and Portugal race for the Shire

Portugal set up a trading post on the Mozambique coast in 1505 and took the Zambezi river ports of Sena and Tete in the 16th century.^[4] In 1886 it signed treaties with France and Germany that in effect recognised its claim to a belt of land across Africa from Mozambique to Angola. Britain answered that it would only recognise claims backed by effective occupation, as the 1885 Berlin Conference had required.^[4] The Portuguese claim was drawn on what became known as the “Rose-coloured Map”.^[10]

The missions sat in the middle of it. Their only way in was up the Zambezi and the Shire, through Portuguese territory.^[10] Early in 1889 Scottish mission circles protested against the threat of Portuguese military action.^[10] Not every mission leader held out, though: in March 1889 the Church of Scotland committee member responsible for Blantyre said the church was ready to accept handing Nyasa to Portugal on stated conditions. In April 1889 terms worked out in Lisbon, which included a concession over Nyasaland, were sent to London, but Lord Salisbury, the British prime minister, judged that Britain gained nothing by them.^[10]

In August 1889 the British consul Harry Johnston met the Portuguese officer Serpa Pinto on the Shire, and left his deputy John Buchanan with orders to declare a protectorate if Serpa Pinto crossed the Ruo, a tributary of the Shire.^[10] After a clash between Portuguese forces and the Makololo on the Ruo in September, Buchanan declared it.^[10] The protectorate over the Makololo, Yao and Machinga lands of the lake area is dated 21 September 1889.^[4] In January 1890 Salisbury sent Portugal an ultimatum, and Portugal gave way.^[10]

“If at least one bank of the Shire beyond Ruo is secured – as I hope to secure it – to England, our Nyasaland will become a kind of African Servia or Paraguay, an inland state with direct fluvial communications with the sea.”^[10]

The lines of 1890 and 1891

In the north, the Anglo-German agreement of 1 July 1890 set the border with German East Africa, now mainland Tanzania. From the Portuguese border it ran along the eastern, northern and western shores of Lake Nyasa to the mouth of the Songwe River, then up the Songwe.^[11][3] That kept the whole northern part of the lake on the British side.^[3][12]

In the west, a British Foreign Office paper of 13 February 1891 let the British South Africa Company operate north of the Zambezi but kept Nyasaland out of its field, behind a defined western limit.^[5] On 14 May 1891 Britain declared a protectorate over the Nyasaland Districts with that same limit, today’s Malawi–Zambia border.^[5][4]

In the east and south, the Anglo-Portuguese treaty of 11 June 1891 gave Portugal only the lake’s eastern shore, south to latitude 13°30′S. From there the line cut across to Lakes Chiuta and Chilwa, followed the Ruo and the Shire, and then ran along the watersheds between the Zambezi and the Shire, and between the Zambezi and the lake, north to the 14th parallel.^[4] Britain kept both banks of the Shire from the lake down to the Ruo, and the line then followed the Shire’s own channel to just below Chiwanga.^[4] Britannica describes the Shire valley running some 400 km south from Mangochi to Nsanje; on the map it is the tail that hangs south between two arms of Mozambique.^[1] An annex let Britain lease land at the Chinde mouth of the Zambezi to land and store goods, and let Portugal do the same on the lake shore.^[4]

A further agreement in 1893 recognised Likoma and Chizumulu, two islands near the eastern shore, as British.^[4] The protectorate was renamed the British Central Africa Protectorate in 1893 and the Nyasaland Protectorate in 1907.^[4][6]

Moving the line into the lake

On 18 November 1954 Britain and Portugal moved the southern lake border from the eastern shore to the median line, the line halfway between the two shores, giving Mozambique 2,471 square miles (about 6,400 km²) of water.^[4] Britain kept Likoma and Chizumulu, both now on Mozambique’s side of that line, together with a belt of water two sea miles wide around each.^[4] That is why two small pieces of Malawi sit in Mozambican waters.

Nyasaland became independent as Malawi on 6 July 1964.^[4] Tanzania and Malawi both accepted the border as it stood at independence.^[3]

The northern lake today

Malawi’s position is that its border with Tanzania follows the lake shore, as the 1890 treaty says. Tanzania’s position is that the border should run down the middle of the lake, citing the practice of dividing lakes at the median line.^[12][13] Officials argued over it briefly in 1967–68, and Tanzania’s first president, Julius Nyerere, conceded the boundary.^[12]

The dispute returned when Malawi licensed a British company to explore for oil and gas in the lake, including the area Tanzania claims. RUSI dates the contract to October 2011, and the row flared in 2012.^[12][13] Mediation through the Southern African Development Community, led by former Mozambican president Joaquim Chissano, held its last negotiations in July 2017. Writing in 2023, RUSI described the dispute as in limbo.^[12]