Greek polymath Eratosthenes of Cyrene was a mathematician, poet, geographer, music theorist, and astronomer. He also served as the Library of Alexandria’s chief librarian. He was also the first to calculate the Earth’s circumference and the tilt of the Earth's axis. Nicknamed Pentathlos, he also invented many scientific terms.
Muhammad ibn Musa al-Khwarizmi was a Persian polymath credited with producing influential works in the fields of geography, astronomy, and mathematics. He is referred to as the founder or father of algebra as he was the first person to recognize algebra as an independent discipline. He also made significant contributions to trigonometry; he produced precise sine and cosine tables.
Apart from being a pioneer of Indology and geodesy, Persian scholar Abū Rayḥān al-Bīrūnī also worked on subjects such as anthropology, math, and ethnography. It is believed he didn’t know his father. He had penned many works, such as the encyclopaedic volume The Chronology of Ancient Nations.
Russian philosopher Peter Kropotkin was a passionate advocate of anarcho-communism. He was also an activist, revolutionary, economist, and sociologist. He was arrested and imprisoned for his activism in 1874. However, he managed to escape and lived in exile for over 40 years in different countries across Europe. He returned to Russia after the Russian Revolution in 1917.
As a child, Alexander von Humboldt was sickly and a bad student. After failing to shine in economics and engineering, he grew up to revolutionize the domain of geography. He is remembered for his research on magnetic storms and his treatise on nature, Kosmos. He also spoke about climate change.
David Harvey is a Marxist economic geographer, podcaster, and a fellow of the British Academy. He is currently a distinguished professor of anthropology and geography at the Graduate Center of the City University of New York (CUNY). He has authored many books and essays and is one of the most cited authors of books in the humanities and social sciences.
Arab geographer Muhammad al-Idrisi created over 70 maps. Born in Ceuta, he spent much of his early life traveling around regions of North Africa, Western Europe, and Asia Minor. Advisor to Sicilian king Roger II, he created the Tabula Rogeriana, one of the most detailed maps of the world.
Strabo was a Greek philosopher, geographer, and historian. He is best remembered for his work Geographica, an encyclopedia of geographical knowledge. Written in Greek during Strabo's time, Geographica holds great historical significance as it houses a descriptive history of places and people from different regions. Among his descriptions were places like the city of Alexandria and India.
Richard Francis Burton was a British explorer, soldier, and scholar. He is best remembered for his explorations in Africa, Asia, and the Americas. Along with John Hanning Speke, Burton was the first European to witness the Great Lakes of Africa. A prolific writer, Burton wrote several scholarly articles about numerous subjects like sexual practices, falconry, human behavior, travel, and ethnography.
Eighth-century alchemist and physician Jabir Ibn Hayyan has been credited with too many written works. Experts believe his vast works may not have been written by a single person. The Jabirian corpus, a collection of his works, is known for its "method of the balance" and its focus on chemistry.
Halford Mackinder was an English geographer, politician, and academic. He is considered one of the founding fathers of geostrategy as well as geopolitics. Mackinder’s work helped establish geography as a separate discipline in the UK. An influential academic, Halford Mackinder held important positions in popular universities, including the University Extension College and the London School of Economics.
14 Carl Ritter
Carl Ritter was a German geographer considered one of the founders of modern geography. He taught history at the University of Berlin and was one of the mentors of the explorer Heinrich Barth, who traveled in Northern and Western Africa. A prolific researcher and writer, Ritter produced a staggering amount of geographical literature in his lifetime.
British naturalist Alfred Russel Wallace is largely remembered for his theory of evolution through natural selection, which inspired Charles Darwin’s studies. He began his career as a surveyor’s apprentice and later introduced concepts such as reinforcement in animals, also known as the Wallace effect. He was awarded the Order of Merit.
Charles Lyell was a Scottish geologist best remembered for his work Principles of Geology, which explains the origin of the earth. He is also remembered for his pioneering explanation of climate change. A close friend of Charles Darwin, Charles Lyell is also credited with influencing many of Darwin's works pertaining to the theories of evolution.
George Everest was a British geographer and surveyor. From 1830 to 1843, he served as Surveyor General of India. His work and contributions were honored by naming Mount Everest, the world's highest peak, after him.
Renowned James Lovelock is best known for propagating the Gaia hypothesis, which states that every living being on planet Earth is part of a single self-regulating superorganism. He is also known for his long association with NIMR, London, and Harvard University and has over 50 patents under his name.
Pytheas was a Greek geographer, astronomer, and explorer. Best known for his legendary voyage to northwestern Europe, Pytheas was the first scientific visitor to witness and describe polar ice, the Arctic, and the Germanic and Celtic tribes. He is also the first explorer to see and describe the midnight sun.
Son of a shoemaker, Flemish cartographer Gerardus Mercator was initially supposed to be a priest. His 1569 world map paved the path for the Mercator projection, which helped people ascertain the exact ratio of latitude and longitude of a particular place. He also coined the term “atlas.”
Douglas Mawson was an Australian Antarctic explorer, geologist, and academic. Counted among the most important leaders of the Heroic Age of Antarctic Exploration, Mawson was honored with a knighthood in 1914. Best remembered for his contribution to Australian geology, Mawson was featured on the Australian one-hundred-dollar note from 1984 to 1996.
25 Piri Reis
Piri Reis was an Ottoman navigator, admiral, cartographer, and geographer. He is best remembered for his Book of Navigation, which contains maps and charts and information on navigational techniques. He gained international recognition in 1929 when a portion of his first world map was discovered at the Topkapı Palace in Turkey. Piri Reis finds mention in several popular video games.
Spanish Islamic scholar Leo Africanus is best remembered for his Description of Africa, which served as a relevant treatise on the geography of Africa. Educated in Morocco, he had traveled through places such as Aswan and Timbuktu. He was later captured and converted to Christianity as Giovanni Leone.
American astronomer, naval officer, oceanographer and author Matthew Fontaine Maury, who first served the United States Navy and then the Confederacy States Navy, made significant contributions in oceanography. His book Physical Geography of the Sea is counted among the first comprehensive books on oceanography. Navies and merchant marines across the world adopted his uniform system of recording oceanographic data.
38 Inge Lehmann
Danish seismologist Inge Lehmann is remembered for her groundbreaking discovery of the Earth’s solid inner core and molten outer core, using seismic waves. While she initially studied math, she later deviated to seismology, with a focus on ascertaining earthquake epicenters. The William Bowie Medal-winning scientist died at age 104.
39 Sven Hedin
Sven Hedin was a Swedish topographer, geographer, photographer, explorer, illustrator, and travel writer. He is best known for making four expeditions to Central Asia. He later shared his experience in a book titled From Pole to Pole. A respected explorer, Hedin was honored with several prestigious awards and medals during his lifetime.
41 Ibn Jubayr
Ibn Jubayr was an Arab geographer, traveler, and poet from al-Andalus. In the years preceding the Third Crusade, he made a famous pilgrimage to Mecca from 1183 to 1185, which he wrote about in great detail in his chronicles. He was a member of an Arab family of the Kinanah tribe and also traveled to Damascus, Mosul, Acre, and Baghdad.
Roman author and geographer Pomponius Mela is best known for penning De situ orbis, later known as De chorographia, which is the earliest known geography treatise in Latin. His work described the Earth to be divided into five zones and four seas, the most important being the Mediterranean.
Elisee Reclus was a renowned French geographer, writer, and anarchist best known for his 19-volume masterwork, La Nouvelle Géographie universelle, la terre et les hommes ("Universal Geography"). He received the Gold Medal of the Paris Geographical Society for this work in 1892. He opposed cruelty to animals and advocated nature conservation. He was also a proponent of naturism.
Adam Sedgwick was a British Anglican priest and geologist. He is credited with guiding and mentoring Charles Darwin during his early years. However, Sedgwick went on to oppose Darwin's theory of evolution. The world's oldest student-run geological society, The Sedgwick Club, was established in his honor in 1880.
Nikolay Przhevalsky was a Russian imperial geographer. A renowned explorer of Central and East Asia, he traveled through regions then unknown to the West. He is credited to have made a substantial contribution to European knowledge of Central Asian geography. However, despite his attempts, he could never reach his ultimate goal, the holy city of Lhasa in Tibet.
James Rennell was an English historian and geographer. A pioneer of oceanography, Rennell is often referred to as the Father of Oceanography. Rennell, who served as a Surveyor General of Bengal, India, is credited with producing some of the earliest accurate maps of Bengal. James Rennell is also credited with co-founding the Royal Geographical Society in London in 1830.
Australian-born British explorer and ornithologist Hubert Wilkins is best remembered for pioneering the use of the submarine for polar exploration. While he initially studied photography and engineering, he later embarked on the world’s first transpolar airplane flight across the Arctic and the first over parts of Antarctica.