The Rwenzori (also known as the Ruwenzori, Rwenzururu or Rwenjura) are a range of mountains in eastern equatorial Africa, located on the border between Uganda and the Democratic Republic of the Congo. The highest peak of the Ruwenzori reaches , and the range's upper regions are permanently snow-capped and glaciated. Rivers fed by mountain streams form one of the sources of the Nile.

The Rwenzori mountains are the highest non-volcanic, non-orogenic mountains in the world.

This uplift divided the paleolake Obweruka and created three of the present-day African Great Lakes: Lake Albert, Lake Edward,

The range is about long and wide. It consists of six massifs separated by deep gorges: Mount Stanley (), Mount Speke (), Mount Baker (), Mount Emin (), Mount Gessi () and Mount Luigi di Savoia (). Mount Stanley has several subsidiary summits, with Margherita Peak being the highest point.

Human history

thumb|upright|left|House and people in [[Kasese District, Uganda]]

The mountains are occasionally identified with the legendary "Mountains of the Moon", described in antiquity as the source of the Nile River. Modern European explorers observed the range beginning in the late nineteenth century, with Samuel Baker reporting what he called the "Blue Mountains" looming in the distance in 1864, and Henry M. Stanley visiting the range in 1875 and 1888, when he recorded the name as "Ruwenzori".

In 1906, the Duke of Abruzzi mounted an expedition to the Ruwenzori, the account of which was subsequently published by Filippo De Filippi. The expedition scaled the highest peaks of the range, several of which were named by the duke, while Mount Luigi di Savoia was named in his honour. Sella's photographic work is conserved at the Museo Nazionale della Montagna in Turin and at the Istituto di Fotografia Alpina Vittorio Sella in Biella, both in Italy. The Makerere University, Uganda, also has a selection of his images.

The first traverse of the six massifs of the Ruwenzori was done in 1975, starting on 27 January and ending on 13 February. The traverse was done by Polish climbers Janusz Chalecki, Stanisław Cholewa and Leszek S. Czarnecki, with Mirosław Kuraś accompanying them on the last half of the traverse.

Since Uganda's independence from the British Empire, the Rwenzori Mountains have repeatedly become sanctuaries to rebel groups. The secessionist Rwenzururu movement fought an insurgency in the mountains in the 1960s. In course of the Ugandan Bush War, the Rwenzururu movement reemerged and continued its struggle until signing a peace deal with Ugandan President Milton Obote's government. In the Bush War's later stages, the National Resistance Army (NRA) rebel force operated in the mountains. After the NRA seized power in Uganda in 1986, another civil war broke out. This time, the Rwenzori Mountains hosted the bases of the National Army for the Liberation of Uganda (NALU) and the "Partie de Liberation Congolaise" (PLC), an anti-Mobutu rebel group. In the early 1990s, a Congolese rebel group known as the National Council of Resistance for Democracy (Conseil National de Résistance pour la Démocratie, CNRD) led by André Kisase Ngandu began to wage an insurgency against Mobutu from the Rwenzori Mountains.

Militias aligned with the old Rwenzururu movement's ideology occupied the Rwenzori Mountains from 1997 to June 2001. In 2020, after being defeated across the border by the Armed Forces of the Democratic Republic of the Congo, some elements of the Allied Democratic Forces moved into the Rwenzori Mountains.

Natural history

Flora

thumb|Lower Bigo Bog at 3400 m in the Ruwenzori, with giant [[lobelia in foreground]]

The Ruwenzori are known for their vegetation, ranging from tropical rainforest through alpine meadows to snow. The range supports its own species and varieties of giant groundsel and giant lobelia and even has a tall heather covered in moss that lives on one of its peaks. Most of the range is now a World Heritage Site and is covered jointly by Rwenzori Mountains National Park in southwestern Uganda and the Virunga National Park in the eastern Congo.

{| class="wikitable" style="text-align:center"

|+Flora vs elevation

|- style="font-weight:small;"

! Meters<br/>Order!! 1500 !! 2000 !! 2500 !! 3000 !! 3200 !! 3400 !! 3600 !! 3800 !! 4000 !! 4200 !! 4400 !! 4600 !! 4800 !! 5000 !! 5100

|-

! Lamiales

|| || ||colspan="4"| Mimulopsis elliotii<br/>Mimulopsis arborescens || || || || || || || || ||

|-

!rowspan="3"| Rosales

|colspan="2"| Prunus africana || ||colspan="5"| Hagenia abyssinica || || || || || ||

|-

|| || || || || || || ||colspan="4"| Alchemilla subnivalis<br/>Alchemilla stuhlmanii<br/>Alchemilla triphylla<br/>Alchemilla johnstonii|| || || || |

|-

|| || || | ||colspan="8"| Alchemilla argyrophylla|| || || || |

|-

! Fabales

|colspan="2"| Albizia gummifera || || || || || || || || || || || || ||

|-

! Cornales

|colspan="2"| Alangium chinense || || || || || || || || || || || || ||

|-

!rowspan="2"| Malpighiales

|colspan="2"| Casearia battiscombei<br/>Croton macrostachyus<br/>Neoboutonia macrocalyx<br/>Symphonia globulifera || || colspan="6"|Hypericum sp <br/> || || || || ||

|-

|| || || ||colspan="5"|Hypericum revolutum<br/>Hypericum bequaertii || || || || || || ||

|-

!rowspan="2"| Asparagales

|| ||colspan="8"| Scadoxus cyrtanthiflorus || || || || || || |

|-

|| || || ||colspan="6"| Disa stairsii || || || || || ||

|-

!rowspan="4"| Asterales

|| || || || || ||colspan="6"|Dendrosenecio erici-rosenii|| || || ||

|-

|| || || || colspan="6"| Dendrosenecio adnivalis<br/>Helichrysum sp.<br/>Lobelia bequaertii<br/>Lobelia wollastonii ||colspan="2"|Helichchrysum guilelmii || || ||

|-

|| || || || || || || || || || colspan="4"|Helichchrysum stuhlmanii || ||

|-

|| || || || || || || ||colspan="4"| Senecio transmarinus<br/>Senecio mattirolii || || || ||

|-

! Apiales

|| || || || || || || ||colspan="4"| Peucedanum kerstenii || || ||

|-

! Myrtales

|colspan="2"| Syzygium guineense || || || || || || || || || || || || ||

|-

! Sapindales

|colspan="2"| Allophylus abyssinicus || || || || || || || || || || || || ||

|-

! Gentianales

|colspan="2"| Tabernaemontana sp. || || || || || ||colspan="4"| Galium ruwenzoriense || || || ||

|-

!rowspan="2"| Ericales

|colspan="2"| Aningeria adolfi-friederici || || colspan="6"| Erica arborea<br/>Erica trimera || || || || ||

|-

|| || || ||colspan="5"|Erica silvatica<br/>Erica johnstonii || || || || || || |||

|-

! Brassicales

|| || || || || || || ||colspan="4"| Subularia monticola || || || ||

|-

! Primulales

|| || || || colspan="6"| Rapanea rhododendroides || || || || ||

|-

! Ranunculales

|| || || || || || || ||colspan="4"| Ranunculus oreophytus<br/>Arabis alpina || || || ||

|-

! Santalales

|colspan="2"| Strombosia scheffleri || || || || || || || || || || || || ||

|-

!rowspan="2"| Poales

|| || || Yushania alpina || || || || ||colspan="4"| Carex runssoroensis<br/>Festuca abyssinica || || ||

|-

|| || || || || || || || ||||||colspan="4"| Poa ruwenzoriensis ||

|-

! Lecanorales

|| || || || ||colspan="5"| Usnea || || || || || ||

|-

! Order<br/>Meters!! 1500 !! 2000 !! 2500 !! 3000 !! 3200 !! 3400 !! 3600 !! 3800 !! 4000 !! 4200 !! 4400 !! 4600 !! 4800 !! 5000 !! 5100

|}

<small>Sources:</small>

Glacial recession

alt=Comparative Images of the Glaciers of the Rwenzori Mountains from 1906 to 2022|thumb|1906 (top left, archive) and 2022 (bottom left) comparative images of Mt Stanley 2012 (top right) and 2022 (bottom right) comparative images of West Stanley Glacier - altitude 4910 m asl created by Klaus Thymann on Project Pressure Expeditions

thumb|[[Ornithologist James P. Chapin on a Ruwenzori expedition under flag of The Explorers Club, 1925]]

An ongoing concern is the impact of climate change on the Ruwenzori's glaciers. In 1906, forty-three named glaciers were distributed over six mountains with a total area of , about half the total glacier area in Africa. By 2005, less than half of these were still present, on only three mountains, with an area of about . Recent scientific studies, such as those by Richard Taylor of University College London, have attributed this retreat to global climate change and have investigated the impact of this change on the mountain's vegetation and biodiversity. In 2012, 2020, 2022, 2024 and 2025; Klaus Thymann led expeditions with the environmental charity Project Pressure creating comparative photographs to visually document the glacier recession, the findings were published in global media including BBC One Planet, The Guardian and Yale Environment 360.

The alteration can be seen in comparative images. As the temperature rises and the glaciers recede, vegetation slowly creeps up the mountain.

In 2025, Project Pressure created the world's first 3D model of the Ugandan glaciers on Mount Stanley using drone photography and GPS coordinates. They found that the surface area of the Stanley Plateau glacier fell by 29.5% between 2020 and 2024. During the drone survey, the exhibition also discovered an accessible ice cave.

thumb|Comparative Image 2012. Mount Stanley (right) and Speke (left)

See also

  • 1966 Toro earthquake

Notes

References

  • Glaciers of the Middle East and Africa, Williams, Richard S. Jr. (editor) In: U. S. Geological Survey Professional Paper, 1991, pp.G1-G70
  • Guide to the Ruwenzori, Osmaston, H.A., Pasteur, D. 1972, Mountain Club of Uganda. 200 p.
  • Recession of Equatorial Glaciers. A Photo Documentation, Hastenrath, S., 2008, Sundog Publishing, Madison, WI, , 144 pp.
  • Tropical Glaciers, Kaser, G., Osmaston, H.A. 2002, Cambridge University Press, UK. 207 p.
  • Ruwenzori, De Filippi, F. 1909. Constable, London. 408 p.
  • Greenpeace article "The Death of the Ice Giants"
  • BBC Article "Fabled ice field set to vanish"
  • Dr Taylor's Homepage, with information about the impact of climate change on Ruwenzori.
  • Kaser et al. 2006, in International Book of Climatology 24: 329–339 (2004)
  • UWM.edu: 1937 aerial photographs of Rwenzori Mountains – University of Wisconsin-Milwaukee Libraries Digital Collections.