Jan. 13, 1888 -- Thirty-three founding members meet at the Cosmos Club, Washington, D.C., to create "a society for the increase and diffusion of geographic knowledge."
October 1888 -- First issue of National Geographic magazine sent to 200 charter members.
1890-91-- First National Geographic Society-sponsored expedition maps the Mount St. Elias region, Alaska; discovers Mount Logan, Canada's highest peak.
Jan. 7, 1898 -- Alexander Graham Bell assumes National Geographic Society's presidency.
February 1903 -- Gilbert H. Grosvenor becomes editor of National Geographic.
January 1905 -- Grosvenor fills 11 pages of the magazine with photos of Lhasa in Tibet. Expecting to be fired, he is instead congratulated by Society members.
July 1906 -- Grosvenor publishes George Shiras III's pioneering flash photographs of animals at night; two National Geographic Society board members resign in disgust, claiming magazine is turning into a "picture book."
April 6, 1909 -- Robert E. Peary and Matthew A. Henson are the first to reach the North Pole in National Geographic Society-supported expedition.
1912-15 -- National Geographic Society-supported expeditions led by Hiram Bingham excavate Machu Picchu, lost mountaintop city of the Inca, in the Peruvian Andes.
1920 -- Gilbert H. Grosvenor becomes president of National Geographic Society (through 1954).
1926 -- National Geographic staff photographer Charles Martin and scientist W.H. Longley make first natural-color underwater pictures.
Nov. 29, 1929 -- Richard E. Byrd achieves man's first flight over South Pole; photographs 60,000square miles of Antarctica from the air.
1930 -- Melville Bell Grosvenor makes first published natural-color aerial photographs.
1941National Geographic Society opens its storehouse of photographs, maps and other cartographic data to President Roosevelt and the U.S. armed forces to aid war efforts.
October 1952 -- Magazine publishes first of many undersea articles by Jacques-Yves Cousteau.
August 1956 -- Magazine publishes deepest undersea photographs made to date, from 25,000 feet down in mid-Atlantic Romanche Trench.
September 1959 -- Color photographs begin to appear regularly on magazine cover.
September 1960 -- National Geographic reports discovery by Louis and Mary Leakey of manlike Zinjanthropus, more than 1.75 million years old.
1961 -- Jane Goodall begins study of chimpanzees in Tanzania's Gombe Stream Park using National Geographic Society funds.
February 1962 -- The magazine publishes its first all-color issue.
June 1962 -- John Glenn carries National Geographic Society flag on first U.S. orbital space flight.
May 1963 -- First Americans conquer Mount Everest in National Geographic Society-supported expedition.
1965 -- National Geographic television programming debuts with the National Geographic Special "Americans on Everest" on CBS.
1967 -- Dian Fossey begins long-term National Geographic Society-funded study of mountain gorillas in Rwanda.
July 1969 -- Apollo 11 astronauts carry National Geographic Society flag to the moon.
1975 -- National Geographic World replaces School Bulletin as young people's publication; circulation reaches 1.3 million by 1976.
April 1979 -- Mary Leakey reports discovery of 3.6 million-year-old footprints believed to be from the slow-walking ancestors of modern man, in the volcanic ash of a riverbed in Tanzania.
1984 -- Undersea archaeology pioneer George F. Bass, supported by the Society, discovers most extensive collection of Bronze Age trade goods ever found beneath the sea, in a 3,400-year-old shipwreck off southern Turkey.
1984 -- National Geographic Traveler, the travel magazine of the Society, is launched.
March 1984 -- Holographic image of an eagle appears on National Geographic cover, pioneering use of holograms in a large-circulation magazine.
1985 -- Under the leadership of Gil Grosvenor, the Society launches a Geography Education Program, with goal of improving geography instruction in school systems.
September 1985 -- Results of R.M.S. Titanic discovery announced at National Geographic Society by Robert D. Ballard.
May 1, 1986 -- Six members of Steger International Polar Expedition, including one woman, are first to reach North Pole by dog sled without resupply since Peary and Henson in 1909.
October 1986 -- Senior Associate Editor Joseph Judge reports after years of study that Christopher Columbus discovered the New World at Samana Cay in the Bahamas.
January 1988 -- Society celebrates its 100th birthday.
December 1988 -- Centennial issue with hologram cover devoted to topic "Can Man Save This Fragile Earth?"
January 1989 -- National Geographic Bee is launched. By 10th anniversary, 5 million students a year participate.
January 1993 -- Paul Sereno of the University of Chicago announces at Society headquarters the discovery of the world's earliest dinosaur.
April 1995 -- Japanese edition of National Geographic magazine begins. It is the first local-language edition of the magazine, of which there are presently 33.
August 1995 -- National Geographic Television becomes a separate, taxable subsidiary company.
May 1996 -- A frozen mummy of an Inca girl, found on a summit in Peru, goes on display for the first time, in Society's Explorers Hall; a record 85,000 people view the exhibit.
June 1996 -- Society launches its website: www.nationalgeographic.com
September 1997 -- National Geographic Channels International is launched; by June 2012, it reaches more than 350 million subscribers in 172 countries in 37 languages.
March 1998 -- Expeditions Council is created. In its first year, it contributes almost $1 million to fund expeditions to some of the most fascinating, little-known places on Earth.
April 1998 -- National Geographic produces its first large-format film, "Mysteries of Egypt."
May 1998 -- Robert Ballard's National Geographic-funded Midway mission finds U.S.S. Yorktown. The WWII carrier rests more than 3 miles under the Pacific.
June 1998 -- National Geographic announces discovery of fossil dinosaurs in China that have distinct feathers, cementing relationship between dinosaurs and birds.
November 1998 -- Paul Sereno announces at the Society the discovery of a huge predatory dinosaur in the Sahara in the Republic of Niger, West Africa. Named Suchomimus tenerensis, the fish-eating dinosaur had a skull like a crocodile and foot-long thumbs.
March 1999 -- High-altitude archaeologist Johan Reinhard discovers three frozen mummies and exquisite Inca artifacts in a grave atop Argentina's Mount Llullaillaco, the world's highest archaeological site.
April 1999 -- Marine biologist Sylvia Earle launches exploration phase of the Sustainable Seas Expeditions, the Society's five-year project to explore and document U.S. marine sanctuaries.
November 1999 -- Renowned mountain photographer/explorer Bradford Washburn announces the revised elevation of the world's highest mountain. Mount Everest is now officially 29,035 feet (8,850 meters), 7 feet taller than the previously accepted height determined in 1954.
November 1999 -- Giant plant-eating dinosaur from the Sahara, Jobaria tiguidensis, is unveiled by paleontologist Paul Sereno at the Society. The primitive, long-necked dinosaur weighed an estimated 20 tons and grew to a length of 70 feet (21 meters).
April 2000 -- National Geographic assembles first class of Explorers-in-Residence to redefine exploration for the new millennium. They are Stephen Ambrose, Robert Ballard, Wade Davis, Sylvia Earle, Jane Goodall, Johan Reinhard and Paul Sereno.
August 2000 -- Using advanced Global Positioning System equipment, a Society-sponsored team pinpoints precise source of Amazon River on Nevado Mismi Mountain in Peru.
November 2000 -- Robert Ballard announces discovery of well-preserved, 1,500-year-old wooden ship in Black Sea.
January 2001 -- National Geographic Channel launches on cable and satellite television in the U.S.
March 2001 -- Society-sponsored "Megatransect" across 2,000 miles of Africa by conservationist Michael Fay captures portrait of pristine wilderness.
March 2001 -- Grantee Meave Leakey announces discovery of 3.5 million- to 3.2 million-year-old fossils that belong to new genus of human ancestors.
September 2001 -- National Geographic for Kids (now National Geographic Explorer) magazine debuts in 50,000 U.S. classrooms.
October 2001 -- Paul Sereno announces discovery of fossil remains of enormous crocodilian, Sarcosuchus imperator, which lived 110 million years ago in the Sahara.
December 2001 -- National Geographic Conservation Trust, new grant-making body to support conservation activities around the world, is launched.
March 2002 -- National Geographic announces it has located Sharbat Gula, the "Afghan Girl," who appeared on the cover of the June 1985 issue of National Geographic magazine. Her photograph became the most recognized in the magazine's 114-year history.
April 2002 -- National Geographic grantee Willy Cock announces discovery of thousands of Inca mummies in Lima, Peru.
May 2002 -- National Geographic's 50th Anniversary Everest Expedition reaches the top of Mount Everest. Team members include Peter Hillary, Jamling Norgay and Brent Bishop, sons of Everest pioneers.
July 2002 -- Robert Ballard announces discovery of what is believed to be the wreck of John F. Kennedy's wartime boat, PT 109, in the South Pacific.
July 2002 -- National Geographic releases its first feature film, "K-19: The Widowmaker," starring Harrison Ford and Liam Neeson.
July 2002 -- Mother-and-daughter paleontologists Meave and Louise Leakey are appointed National Geographic Explorers-in-Residence.
September 2002 -- National Geographic World magazine is renamed National Geographic Kids. Classroom magazine National Geographic for Kids is renamed National Geographic Explorer.
November 2002 -- National Geographic-Roper Geographic Literacy Survey of some 3,000 18- to 24-year-olds in nine countries showed young Americans were outperformed by most of their international counterparts. The U.S. scored second to last.
September 2003 -- National Geographic Speakers Bureau is formed, with more than three dozen journalists, photographers, adventurers and scientists in the program.
March 2004 -- National Geographic All Roads Film project launches, providing a global platform for indigenous and under-represented minority-culture filmmakers around the world to showcase their talents and cultures to a broader audience.
May 2004 -- National Geographic Home Collection of furniture debuts.
June 2004 -- Society Chairman Gilbert M. Grosvenor celebrates his 50th anniversary at National Geographic and is awarded the Presidential Medal of Freedom.
September 2004 -- First class of National Geographic Emerging Explorers is announced. Selected annually, they are gifted adventurers, scientists and researchers making an important contribution to world knowledge while still early in their careers.
October 2004 -- Honduras becomes first country to adopt National Geographic's Geotourism Charter, committing to be a sustainable destination, managing tourism development wisely. Geotourism is defined as tourism that sustains or enhances the geographical character of a place.
January 2005 -- National Geographic teams with Siemens to sponsor a five-year project CT scanning ancient Egyptian mummies, including King Tutankhamun.
March 2005 -- Research grantee Dean Falk announces results of a sophisticated study of the brain of the fossil known as "Hobbit," a dwarf-like hominid discovered in Indonesia.
April 2005 -- National Geographic launches the Genographic Project, a multi-year DNA study to map humanity's migratory journey through the ages, in partnership with IBM and the Waitt Family Foundation.
April 2005 -- Anthropologist and population geneticist Spencer Wells is appointed a National Geographic Explorer-in-Residence.
May 2005 -- National Geographic sponsors two teams to recreate the face of King Tut using information from the CT scans obtained in January 2005. The reconstructed face is unveiled on the June 2005 cover of National Geographic magazine.
June 2005 -- National Geographic Feature Films partners with Warner Independent Pictures to market and distribute "March of the Penguins," the second-highest-grossing feature documentary film ever released.
September 2005 -- National Geographic magazine publishes a special Katrina issue on the hurricane and its aftermath. It is the most accelerated issue of the magazine ever produced — on newsstands just over three weeks after the hurricane hit.
November 2005 -- Wildlife filmmakers Dereck and Beverly Joubert are appointed National Geographic Explorers-in-Residence.
April 2006 -- National Geographic, in collaboration with the Maecenas Foundation for Ancient Art and the Waitt Institute for Historical Discovery, announces discovery, translation and authentication of ancient codex containing Gospel of Judas.
May 2006 -- National Geographic establishes its Fellows program to encourage flow of ideas between the Society and field experts.
October 2006 -- Paleoanthropologist and National Geographic research grantee Zeresenay Alemseged announces find of fossil of world's oldest infant, dating from 3.3 million years ago, in Ethiopia.
October 2006 -- National Geographic wins the 2006 Prince of Asturias Award for Communication and Humanities.
October 2006 -- With support from Lindblad Expeditions, National Geographic launches Young Explorers Grants Program to help budding scientists, conservationists and explorers aged 18-25 get a start in their careers.
November 2006 - Author Jared Diamond and conservationist J. Michael Fay are appointed National Geographic Explorers-in-Residence.
January 2007 -- Grantee Mike Parker Pearson announces discovery of the remains of houses of the builders of Stonehenge.
September 2007 -- National Geographic fellow Chris Rainier and grantee David Harrison announce top hotspots around the world where languages are disappearing most rapidly. Enduring Voices Project, a program to document and revitalize vanishing languages, is launched.
July 2008 -- Archaeologists funded by National Geographic announce discovery of the remains of George Washington's boyhood home at Ferry Farm near Fredericksburg, Va.
August 2008 -- Explorer-in-Residence Paul Sereno announces discovery of a Stone-Age graveyard in the Sahara, providing an unparalleled record of life when the region was green.
November 2008 -- National Geographic opens its first global retail store on London's Regent Street.
November 2009 -- "Terra Cotta Warriors: Guardians of the First Emperor" exhibit opens at National Geographic Museum, with 15 terracotta figures, the largest number ever to travel to the United States.
November 2009 -- Explorer-in-Residence Paul Sereno announces discovery of suite of five ancient crocs, three of them new species, in the Sahara.
January 2011 -- On Gilbert M. Grosvenor's retirement, John M. Fahey becomes chairman of National Geographic; Timothy Kelly replaces Fahey as president.
June 2011 -- Filmmaker James Cameron and marine ecologist Enric Sala are named National Geographic Explorers-in-Residence.
July 2011 -- Government of Peru bestows highest civilian award "Orden del Sol del Peru" on National Geographic Society executives for helping retrieve a collection of ancient artifacts taken from Machu Picchu nearly 100 years ago
December 2011-- National Geographic launches its Global Exploration Fund, an initiative to fund research, conservation and exploration projects through regional centers around the globe.
March 2012 -- Explorer-in-Residence James Cameron becomes first person to dive solo to the Mariana Trench as part of DEEPSEA CHALLENGE, a joint scientific expedition by Cameron, National Geographic and Rolex to conduct deep-ocean research and exploration.