An introduction to the history of West Africa , Fage, J. D. , Cambridge : University Press - 1966

World history from earliest times to 1800 , Judge, Harry , Oxford : Oxford University Press - 1988

The Cambridge medieval history , J.B. Bury , Cambridge : University Press - 1968-1981

An Encyclopedia of World History , Langer, William L. , Houghton Mifflin Co. - 1973

Ancient India: From the Origins to the XIII Century A.D. , Albanese, Marilia , White Star - 2001

Ancient China: Chinese Civilization From Its Origins To the tang Dynasty , Scarpari, Maurizio , Barnes & Noble - 2006

Cultural Atlas of Russia and the Soviet Union , Robin Milner-Gulland - Nicolai Dejevsky , Facts on File; New edition edition - 1989

The Cambridge history of Latin America , Bethell, Leslie , Cambridge : Cambridge University Press - 1984-1995

A dictionary of ancient history , Speake, Graham , Oxford, UK ; Cambridge, Massachusetts : B. Blackwell - 1994

A short history of Japan , Clement, Ernest Wilson , Tokyo : Kyo Bun Kwan - 1931

The Cambridge Illustrated Atlas of Warfare: Renaissance to Revolution, 1492-1792 , Black, Jeremy , Cambridge University Press - 1996

Crónica de América , Burrel i Floría, Guillem , Quinto Centenario ; Barcelona : Plaza & Janés, D.L. - 1990

A political chronology of the Middle East , Lea, David , London : Europa Publications - 2001

A political chronology of Central, South and East Asia , Preston, Ian , London : Europa Publications - 2001

A political chronology of South-East Asia and Oceania , David Lea - Colette Milward , London : Europa Publications - 2001

A history of Japan , Totman, Conrad , Malden, MA : Blackwell - 2005

The Cambridge history of Russia , Perrie, Maureen (1946-) - Lieven, Dominic - Suny, Ronald Grigor , Cambridge : Cambridge University Press - 2006

A Concise History of India , Metcalf, Barbara Daly , Cambridge University Press - 2001

The Routledge atlas of Russian history , Gilbert, Martin (1936-2015) , London ; New York : Routledge - 2007

Historical dictionary of India , Mansingh, Surjit , Lanham (Maryland) : Scarecrow Press - 2006

The Cambridge Illustrated History of China , Ebrey, Patricia Buckley , Cambridge University Press - 1996

Historical dictionary of Russia , Raymond, Boris , Lanham (Md.) ; London : Scarecrow Press - 1998

Historical dictionary of Iran , Lorentz, John H. , Lanham (Mariland) : The Scarecrow Press - 2007

Historical dictionary of Pakistan , Burki, Shahid Javed , Lanham, Maryland : The Scarecrow Press - 2006

Atlas des peuples d'Europe centrale , Jean Sellier et André Sellier , Editions la Decouverte - 1994

Atlas des peuples d'Europe occidentale , Jean Sellier - André Sellier - Anne Le Fur , La Découverte - 1996

Historical Atlas of Central America , Carolyn Olive Hall - Hector Perez Brignoli , Univ of Oklahoma Pr; Edición: New - 2003

Historical atlas of Britain , Malcolm Falkus - John Gillingham , London : Granada - 1981

Atlas of the Greek and Roman world in antiquity , Nicholas G.L. Hammond , Park Ridge, New Jersey : Noyes Press - 1981

Storia illustrata di Roma antica. Dalle origini alla caduta dell'impero , Melani, Chiara , Giunti Editore - 2000

Le grand livre de l'histoire du monde , Pierre Vidal-Naquet , France Loisirs - 1986

Le grand atlas de l'histoire mondiale , Le Roy Ladurie, Emmanuel , Paris : Encyclopaedia Universalis : Albin Michel, D.L. - 1991

Atlas histórico universal y de España , Juan Antonio Sánchez García-Sauco , Madrid : Santillana - 2005

Atlas histórico , Editorial Marín , Barcelona : Marín, D.L. - 1989

Atlas histórico, cronología , Lexis 22 , Barcelona : Círculo de Lectores - 1983

Atlas Geo-Histórico Universal Balboa , Barcelona : Ramón Sopena, D.L. - 1990

Nuevo atlas universal geográfico-Histórico , Martínez de Salinas, María Paz , Barcelona : Naute - 1991

The Penguin atlas of ancient history , McEvedy, Colin , New York : Penguin Books - 1976

Atlas of ancient civilizations , Branigan, Keith , New York : The John Day Company, D.L. - 1975

Atlante illustrato delle civiltà antiche , Millard, Anne , Milano : Bompiani - 2000

Atlas historique , Duby, Georges , Larousse - 1978

Africa from early times to 1800 , Mac Ewan, P.J.M. , London : Oxford University Press - 1968

Historical atlas of Africa , A. J. F. Ajayi - Michael Crowder , Harlow (England) : Longman - 1985

A historical atlas of South Asia , Schwartzberg, Joseph E. , Chicago : The University of Chicago Press - 1978

An historical atlas of Central Asia , Yuri Bregel , Leiden ; Boston : Brill - 2003

Historical atlas of South-East Asia , Pluvier, Jan M. , Leiden : E.J. Brill - 1995

Ancient history atlas , Grant, Michael , London : Weidenfeld and Nicholson - 1971

L'atlas du monde antique , Oliphant, Margaret , Paris : France Loisirs - 1993

Diverses Cartes et Tables, La Geographie Ancienne, pour la Chronologie, et pour les Itineraires, et Voyages Modernes , Duval, Pierre , A Paris : Chez l'Auteur, en l'isle du Palais sur le Quay de l'Orloge, au coin de la Rue de la Harlay - 1677

The Hamlyn historical atlas , Moore, R. I. , London : Hamlyn - 1981

World History Atlas , Devos, W. - Geivers, R. , Madrid : Bruño - 1997

Atlas of World History , Barraclough, Geoffrey , Times Books - 1989

The black death, 1346-1353 , Ole J. Benedictow , Boydell Press - 2004

Manuale di storia delle religioni , Giovanni Filoramo, Marcello Massenzio, Massimo Raveri y Paolo Scarpi , Laterza - 1998

Historia de la Filosofía , Julián Marías , Alianza Editorial - 2001

A little history of philosophy , Nigel Warburton , Yale University Press - 2012

The philosophers , Ted Honderich , Oxford University Press - 1999

50 philosophy ideas you really need to know , Ben Dupre , Quercus - 2007

50 Religious Ideas You Really Need to Know , Peter Stanforf , Quercus - 2010

The great war for civilization , Robert Fisk , Knopf - 2005

Science: A History 1543 - 2001 , John Gribbin , Penguin - 2003

History of mankind : cultural and scientific development , Allen & Unwin - 1965

Manual de historia universal , Madrid : Espasa-Calpe - 1958

Rome et la Méditerranée occidentale jusqu'aux guerres puniques , Heurgon, Jacques , Paris : Presses Universitaires de France - 1969

Prehistoria e historia del próximo oriente , Ripoll Perelló, Eduardo , Barcelona : Labor - 1975

La crisis del Imperio romano: de Marco Aurelio a Anastasio , Remondon, Roger , Barcelona : Labor - 1973

Los métodos de la historia: introducción a los problemas, métodos y técnicas de la historia demográfica, económica y social , Ciro Flamarión S. Cardoso - Héctor Pérez Brignoli , Barcelona : Crítica - 1981

Atlas de historia de España , Fernando García de Cortázar , Barcelona : Planeta - 2005

dtv-Atlas Weltgeschichte: Von den Anfängen bis zur Gegenwart , Hermann Kinder - Werner Hilgemann , Dtv Deutscher Taschenbuch - 2010

Atlas histórico de España y Portugal : desde el Paleolítico hasta el siglo XX , López-Davalillo Larrea, Julio , Madrid : Síntesis - 1999

Atlas histórico de Europa: desde el Paleolítico hasta el siglo XX , López-Davalillo Larrea, Julio , Madrid : Síntesis - 2001

Atlas histórico mundial: desde el Paleolítico hasta el siglo XX , López-Davalillo Larrea, Julio , Madrid : Síntesis - 2000

Atlas histórico de Latinoamérica : desde la prehistoria al siglo XXI , Lucena Salmoral, Manuel , Madrid : Síntesis - 2005

Atlas of World History , John Haywood , Cassell - 1997

The Times atlas of the Bible , Pritchard, James B , London : Times Books - 1987

Atlas histórico universal , Juan Avilés Farré , El País-Aguilar - 1995

Atlas histórico , Joan Roig Obiol , Barcelona : Vicens-Vives - 2004

Atlas histórico del mundo griego antiguo , Adolfo J. Domínguez - José Pascual , Madrid : Síntesis - 2006

Atlas of World History , Kate Santon - Liz McKay , Parragon Publishing - 2005

Historia universal , Navarro, Francesc , Madrid : Salvat - 2004

Historia , National Geographic. Barcelona : RBA, - 2012-2014

Chronology of the World: The History of the World From the Big Bang to Modern Times , Asimov, Isaac , Harper Collins Publishers - 1991

Persian Fire: The First World Empire, Battle for the West , Holland, Tom , Abacus; Edición - 2006

Ancient Warfare Books , Osprey publishing - 1986

Historical Atlas: A Comprehensive History of the World , Geoffrey Wawro , Millennium House - 2008

Introducción a la historia de África negra , Cortés López, José Luis , Madrid : Espasa-Calpe - 1984

Mesopotamia , Ascalone, Enrico , University of California Press - 2007

Age of Extremes: The Short Twentieth Century 1914-1991 , Eric Hobsbawm , Abacus - 1994

Historias del viejo mundo , Madrid : Información e Historia, D.L. - 1994

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Past Worlds: Times Atlas of Archaeology , Times Books - 1988

Der Hellenismus und der Aufstieg Roms , Pierre Grimal , Frankfurt, a. M. Fischer Verlag - 1965

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Encyclopaedia Britannica , https://www.britannica.com/

Wikipedia, the free encyclopedia , https://www.wikipedia.org/

The Centennia Historical Atlas , Frank Reed , http://www.historicalatlas.com/

World History Maps , John C. Nelson , http://www.worldhistorymaps.com/

World History Atlas , Francis E Lodge , http://www.atlasofworldhistory.com/

Histoire mondiale , Patrice Henrio , http://histoiremondiale.free.fr/index1.htm

Euratlas: History and Geography of Europe and the World , http://www.euratlas.com/

Historical maps , University of Texas , http://www.lib.utexas.edu/maps/historical/index.html

Historical Atlas of the Twentieth Century , http://users.erols.com/mwhite28/20centry.htm

History Atlas , Jeff Moran , http://www.historyatlas.com/

Animated Atlas of African History 1879-2002 , http://www.brown.edu/Research/AAAH/map.htm

Guide and Index of World History, Dynasties and Lists of Rulers , http://www.friesian.com/histindx.htm

Maps of South Asia , Dr. Frances W. Pritchett , http://www.columbia.edu/itc/mealac/pritchett/00maplinks/index.html

Ancient History , http://www.ancient.eu/

David Rumsey Map Collection , David Rumsey , http://www.davidrumsey.com/

GeaCron is a complementary tool for the study of history and for the information contained in documentary sources, historiographies, and encyclopedias. As History is a subject that is often open to interpretation, we are open to the collaboration of all those interested in World History who wish to provide their knowledge, suggest a modification, or any other kind of contribution.

After collecting information from maps encompassing 5000 years and the whole world, using many different sources (libraries, historical atlases, university sources, Internet,…), we have introduced all those data into the temporal GIS database that we have developed, starting with 3000 B.C., year by year and for the whole world.

We studied in detail every year from a historical point of view to ensure that the borders are correct and that there is consensus among the various documents and geographical and geopolitical files considered.

When there is no consensus on the location of a specific border, according to the sources, we’ve adjusted a specific political entity to its relevant geographical features. This situation occurs, especially, in the ancient world. Sometimes, moving forward in time, documents show that a particular location was integrated into a political entity on a specific date that was already integrated into our maps after adjustment. In such cases we’ve gone back in time and readjust borders to give coherence to the maps.

In other cases there is no consensus on whether a particular area belongs to different countries sharing borders. Just as in the previous case, we’ve looked for consistent information in later years.

There may be no consensus on dates. Again, after analyzing the available sources, we’ve looked for consistency in later years.

For recent dates and territorial conflicts, we’ve taken into consideration the country which is militarily occupying the territory and if that country is recognized by most of international community.

If there is a general consensus on an issue, we’ve shown it on the maps.

For ancient world we have used “short chronology”.

When the exact date of the establishment of a political entity is not known, an approximate date has been set.

Our starting point is that, whenever there is a change of borders, it is due to some relevant historical reason, and as we think that the encoding of this information is very valuable and essential, we've been careful to associate a fact to any change of borders. All this information is contained in the GeaCron's database.

A unique color, and at least one link, has been assigned to every political entity.

The maps show the historical situation of the world at the beginning of every year.

The maps show the high level political entities. We consider a political entity when it responds, according to available documentation, to the category of state, empire, kingdom or country, with documented governments or dynasties. At this moment, we do not show information inside political entities or internal borders.

Methodology Flowchart