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Core Genealogy:

A Genealogical History of the Modern World

Core Genealogies

Basic Premise

Every cultural group has a Unifying Ancestry (core genealogy) to which all members of the group can link their ancestry.  Once you have linked your genealogy to the core, you are related to every other member of your group who has also linked their ancestry.  This provides a completeness metric for your genealogy.

For example:

  • Irish seek lineages to Milesius (ca 1745 BC)

  • Italians seek lineages to Romulus (ca 778 BC)

  • Scandinavians seek lineages to Woden (ca 215)

  • French seek lineages to Merovech (ca 419)

  • Scotts seek lineages to Fergus Mor (ca 445)

  • English seek lineages to Icel of Mercia (ca 463)

  • Russians seek lineages to Rurik (ca 845)

The challenge is finding a core genealogy that is based on historical fact rather than cultural tradition.  A viable core genealogy should extend to the present, be highly interconnected, and cover as many cultural groups as possible.

Core Genealogy

For persons of Western European descent, a core genealogy exists based on the common ancestors of the royal lines of Great Britain, Spain, Belgium, Netherlands, Denmark, Norway, and Sweden.  Any descendant of the common ancestors can be selected and a core genealogy formed based on the ancestors of that person.


The royal lines connect to multiple cultural groups:

  • Anglo Saxons - Kings of Essex, Sussex, Wessex, Mercia, Northumberland, and Kent

  • Asturia - Imams of Seville

  • Carolingians - French descendants of Charlemagne

  • Davidic King list back to Adam and Eve

  • Eastern Roman Emperors of Byzantium

  • Egyptian Pharaohs

  • English peerage to the 1800s

  • Franks - descendants of Clovis I

  • German peerage

  • Irish Monarchs  - High Kings of Northern Ui Neill, Southern Ui Neill, Leinster, Meath(Tara), Munster(Cashel), Ulster(Aileach), Breifni, Tyrone(Ulidia, Oriel), Dublin

  • Latin Kings of Jerusalem during the Crusades

  • Lombards - Italian and French lineages

  • Macedonians - Cousins of Alexander the Great

  • Merovingians - Frankish descendants of Merovech

  • Ostrogoths - King Theodoric the Great

  • Persians - Darius the Great

  • Ptolemaic rulers of Egypt down to Cleopatra

  • Romans - Emperors back to Julius Caesar

  • Russians - Dukes of Kiev and the Tsars

  • Scandinavians - Kings back to Oden

  • Scots - Kings of Dalriada

  • Spanish - Kings of Aragon, Castile, Leon, Navarre

  • Vandals - Kings Geiseric, Hunneric, and Hilderic

  • Visigoths - Kings Theodoric, Alaric, and Athanagild

  • Welsh - Kings of Gwynedd, Deheubarth, and Powys


The royal lines are highly intermarried.  In the Research Genealogy, the royal lines have 38,184 common ancestors.  Their intermarriage is illustrated by finding the number of ascents to Charlemagne:​​

  •  2.9 billion - King Willem of the Netherlands

  •  4.2 billion - King Philippe of Belgium

  •  4.9 billion - King Harald V of Norway

  •  5.3 billion - King Charles III of Great Britain

  •  6.6 billion - King Carl XVI of Sweden

  •  7.2 billion - King Frederik X of Denmark

  • 14.1 billion - King Felipe VI of Spain

Connecting to one royal line provides connections to the other royal lines.

A viable unifying ancestry is the ancestors of Prince George of Cambridge (56,796 persons).  This automatically includes the common ancestors of the royal lines of Europe, links to all of the above cultural groups, is highly intermarried, and extends to the present time.


The viability of a Unifying Ancestry can be evaluated by analyzing the average connection year for linking your genealogy to the core genealogy.  For persons born in the 20th century, the average connection year is 1622 for a core genealogy based on Prince George. Connecting to the core genealogy typically requires tracing your ancestry back for 12 generations.

You will then find that typically 99% of your ancestors and roughly 1% of your DNA will come from the core genealogy.  It will take from 10-34 generations to link your ancestry to the core genealogy.  It will take 50-60 generations to link your ancestry to a progenitor for Western Europeans.

The internal connectedness of a core genealogy can be evaluated by analyzing the "own-cousin" relationship of each member of the core.  Every person has an ancestor to which they have multiple ascents.  Their "own-cousin" relationship is the number of generations minus one to that ancestor.  You can trace your ancestry up one of the ascents and your cousin relationship down the other ascent.

For a highly interconnected core genealogy, about half of the members should have an own-cousin relationship. For the core genealogy based on Prince George, 30.056 of the 56,796 ancestors have an own-cousin relationship. The average value is 6.4 cousin.

The ancestral connection point for the own-cousin relationship is limited to members of the unifying ancestry who have multiple children who are also members of the core genealogy.  For Prince George, 9,609 ancestors have multiple core children.  Interestingly, the ancestral connection points comprise only 3,239 persons.  These persons provide a "short" list of potential ancestors to which you would link your ancestry.  Charlemagne (747-814) is one of the connection points.  The connection point with the most own-cousin connections is Richard I of Normancy (933-996).

This analysis illustrates why typical goals of a person assembling a genealogy are to find an ascent to Charlemagne and a royal descent.  A better goal is to connect to the unifying ancestry.

The Research Genealogy can be characterized by counting the number of generations from a person born in the 20th century to notable events:

  •   6 generations - typical lineage coalescence point for own cousin relationship

  •   11 generations - typical connection to unifying ancestry for Western European descendants

  •   27 generations - analytic estimate for connection to a progenitor for Western European descendants

  •   35 generations - average number of ascents exceeds 200 million.  This is the typical upper limit for connection to unifying ancestry.

  •   42 generations - connection to Charlemagne, born 747 CE

  •   49 generations - analytic estimate for when all members of the generation are progenitors

  •   52 generations - first progenitor identified in Research Genealogy, Aethelberht II of Kent, born 696 CE

  •   76 generations - connection to Darius I of Persia, born 558 BCE

  •   119 generations - connection to Tao I, Pharaoh of Egypt, born about 1650 BCE with 400 quadrillion ascents

About Us

CoreGen3 Program


Mac Version for up to 350,000 persons is at

Search for CoreGen3


Windows version for up to 700,000 persons is at

Search for CoreGen3

To download a pdf paper on CoreGen3, click the link below:

 To download a pdf book on CoreGen2  

 (an interface with one window), click the  link below.  The book describes the    algorithms used for graph traversal.


For each person in the input gedcom file, the properties that can be displayed include:

  • PersonID, FatherID, MotherID

  • Birth and Death Years and Dates

  • Age, Alias, Title

  • First and Last Names

  • Location of Birth, Baptism, Death, Burial, Residence and First Marriage

  • Group Membership

  • Prefix, Suffix

Root Operations

For each person in the genealogy, the operations that can be performed include:

  • Error analysis for date biological feasibility

  • Ancestors, Number of ascents

  • Descendants, Number of descents

  • Ancestral and Descendant fractional distribution

  • Relatives, Treetops, Lineage from root to ancestral person

  • Partition based on Extended Families

  • Connection between two persons across minimum number of families

  • Link that gives the shortest path between two persons

  • Lineage of Maximal Ascent

  • Distributions for Nobles, Sources, birth Country

  • Own Cousin, Parental Cousin

  • Progenitors

What We Offer

Research Genealogy


The Research Genealogy was assembled over a 33-year period by typing in information for 50 persons per night.  A total of 2125 sources were used, ranging from history books, to compiled genealogies, to genealogy web sites.

For every person, the minimal information included:

  • First and last names

  • Birth year (estimated if not available)

  • Sources

  • Relationship to at least one other person in the genealogy

  • Country designation in each birth location

The genealogy contains 348,844 persons, spans all of the cultural groups in Western Europe, and provides a testbed for evaluating potential Core Genealogies.  An average of 1.6 sources is provided for each person.

The Research Genealogy is published at


Unfortunately, almost every source that was accessed contained errors.  To attempt to build a coherent genealogy, a biological feasibility constraint was applied to every date  Ages at marriage, birth of a child, and death were checked for feasibility.  All persons in the genealogy satisfy these constraints except for the Davidic King List, which uses traditional dates proposed by James Ussher, the Primate of Ireland.  

In the construction of the Research Genealogy, the internal consistency of sources was used to assess reliability. Also, sources providing more detailed information were deemed more reliable.  When discrepancies occurred, information from the more reliable source was used.


The Research Genealogy includes lineages for:

  • Royal lines

  • British peerage

  • U. S. President

  • U. S. President spouses

  • Notable persons alive today

  • Historically significant persons

An attempt was made to link all persons listed in Palmer's History of the Modern World to the Research Genealogy. This provides a metric for validating the concept of a Core Genealogy.  87% of the persons (627 of 719) could be linked.  Information available for the remaining persons proved insufficient to link them in.

The Concept of a Core Genealogy started with the 60 million persons alive in 1300, since the number of ancestors in a single generation at that time is greater than this number.  By selecting a Core Genealogy based on the common ancestors of the royal lines, the size is reduced to 38,533 persons.  By examining the internal own-cousin relationship coalescence points, the number is further reduced to 3,239 persons.  By imposing constraints for:

  • At least 200 million ascents

  • Not an ancestor of Charlemagne

  • Born after 200 AD

  • Have descendants in the 20th century

  • Have at least 1000 descendants that are not descendants of Charlemagne

  • Have at least 52 generations from Prince George to the progenitor

the number of progenitors is reduced to 12 persons.  This represents a minimal set of progenitors for linking your genealogy into a Western European genealogy.  Linking to the Unifying Ancestry automatically gives you lineages to the progenitors.

The CoreGen3 program together with the Research Genealogy provides a Genealogical History of the Modern World.  It is possible to trace lineages to historically important people.  You can also trace lineages for notable persons alive today.  You can determine how a group of persons are related, and find common ancestors.

An example is the set of common ancestors of the U. S. Presidents.  They are all linked to the Core Genealogy, implying that the Presidents are cousins of George Washington.

George Washington     Source

John Adams             8C3R*

Thomas Jefferson       9C1R*

James Madison         10C2R*

James Monroe          11C3R*

John Quincy Adams      8C

Andrew Jackson        H7C3R*

Martin van Buren      11C2R*

William Harrison      10C

John IV Tyler         10C3R*

James Polk            11C3R*

Zachary Taylor        H9C1R*

Millard Fillmore       9C4R*

Franklin Pierce        9C

James Buchanan        11C2R*

Abraham Lincoln        8C4R*

Andrew Johnson        10C4R*

Ulysses Grant          6C2R*

Rutherford Hayes       7C3R*

James Garfield         8C4R*

Chester Arthur        10C3R*

Stephen Cleveland      7C5R*

Benjamin Harrison     10C2R*

William McKinley       8C4R*

Theodore Roosevelt     8C6R*

William Taft           6C5R*

Thomas Wilson         11C3R*

Warren Harding         8C5R*

John Coolidge          6C6R*

Herbert Hoover         9C7R*

Franklin Roosevelt     8C4R*

Harry Truman           9C6R*

Dwight Eisenhower     12C5R*

John Kennedy          11C7R*

Lyndon Johnson         9C7R*

RIchard Nixon          8C7R*

Gerald Ford            7C8R*

James Carter          H9C6R*

Ronald Reagan          8C8R*

George Herbert Bush    7C8R*

William Clinton        9C6R*

George Walker Bush     7C9R*

Barack Obama           3C8R*

Donald Trump          11C8R*

Joseph Biden          11C8R*

The number of common ancestors is 9,855.  The five most recent are:

Blanche de Brienne     (1251)

Blanche d'Artois       (1248-1302)

William II de Fiennes  (1244-1302)

Eleanor of Castile     (1240-1290)

Edward I Plantagenet   (1239-1307)


The Research Genealogy contains 8,530 persons who were born after 1940.  All of the information in the Research Genealogy was derived from public sources and is discoverable by any person with network access.  To provide privacy, the information displayed for persons born after 1940 is restricted to initials and a birth year.  No information is provided about full names, locations, full dates, sources, or occupations for persons born after 1940.

However, full information is provided about public figures who are documented in WikiTree and Wikipedia.  Examples

include Royal Lines, U. S. Presidents, politicians, actors, singers, and entrepreneurs.

If the public information is deemed an invasion of privacy, send a message to the contact listed below.  If a source is provided for your information, you should also consider contacting the original source of the information.

No information is collected about any user of the CoreGEN3 program.  The CoreGEN3 program does not

modify any user data.  Instead, information that is exported from the CoreGEN3 program can be input as a Gedcom file into your personal genealogy.

Why Us

CoreGen3 Code

The CoreGen3 program runs on Mac computers, OS version 13.4.1, and Windows computers.  The Mac version supports genealogies with up to 350,000 persons.  The Windows version supports up to 700,000 persons.CoreGen3 is freely available at the Mac App Store (SM) and the Microsoft Store.  The components of the program include:

  • Gedcom file parser for input

  • Gedcom file exporter for output

  • Graph database

  • Data store

  • Graph traversal algorithms

  • Table-based display using sort, search, and scroll

  • Restart file

  • Summary statistics

Group Operations

Up to 8 groups can be defined.  The Research Genealogy provides 7 default groups for Root person, Progenitors, Royal Lines, U.S. Presidents, Magna Charta Sureties, Spouses of U.S. Presidents, and Notable Persons.


Operations that can be applied to each group include:

  • Addition/deletion of persons from group

  • Relationship of the Root Person to each member of the group

  • Common Ancestors

  • Common Descendants

  • Common Relatives

Core Operations

Any person can be selected as the Core Root person for a Core Genealogy. The ancestors of the person comprise the Core Genealogy.  Operations that can be applied include:

  • Select a Core Root person

  • Save and display a Core based on the name of the Root Person

  • List saved Core genealogies

  • Connection year

  • # Core Ancestors

  • Core Own-Cousin relationships. This includes a distribution of Own-Cousin relationships by century for all of the ancestors of the Core person.





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