In all of the readings I've done about the Royal Couple, I've never come across the allegation that Louis and Antoinette were second cousins once removed.

http://www.answers.com/topic/louis-xvi-of-france

I've tried to figure out the family tree to identify the common relative(s), but geneology is as foreign to me as math. My attempts at identification have failed. Here are some guides to assist with identification. Is anyone more proficient in geneology to help identify their 'shared great-grandparent but not grandparent'?

http://www.answers.com/topic/cousin

According to the family tree I've found in A. Fraser's biography, their had a common ancestor in emperor Leopold I, who, however, was MA's great- grandfather, but Louis great-great-grandfather (I hope this is the right word).
To make things clearer: Louis' mother, Maria Josepha, was daughter of the Elector of Saxony, who, in turn, was the son of emperor Joseph I, who was Leopold VI's son.
Antoinette's mother, empress Maria Theresa, was daughter of emperor Charles VI, who in turn was son of Leopold VI.
So, actually, they were distant relatives.

Marie Antoinette's Grandmother (Her father's mother) was the daughter of Louis XIV's brother Phillipe (his second marrriage).
More common relatives are Louis XIII and Anne of Austria - whom happen to be MA's Great-Great-Grandparents.

Wow! Thank you so much for the family tree information Rosalie and Lilly. It would have taken me weeks to figure that out and even then the outcome would be questionable. I wonder if the taboo of first cousins marrying was in place at this time. I'm not aware of any unstable monarchs around this time, except for George III of England. I'm not sure of the source of his illness.

First cousins absolutely did marry. As a matter of fact, there are parents in the Orleans line who were first cousins. Here's how that goes -

Louis XIII & Anne of Austria (Parents)

Louis XIV and his brother Philippe Duc d'Orleans

Louis XIV (legitimized) daughter marries Phillipe's son by his second wife. The two were first cousins. This son of Phillipe was known as Phillipe II Duc d'Orleans/The Regent during the minority of Louis XV. He was the brother of Marie Antoinette's grandmother.
This is also where the Palais Royal comes into the hands of the Orleans - King Louis XIV gave it to his daughter and his nephew when they were married.

Copied from the internet:


It was Philippe and his second wife, the famous court writer Elizabeth Charlotte of the Palatinate, founded the modern House of Orléans - their surviving son being the Regent of France for the young Louis XV.

As a Fils de France, Philippe was styled as Philippe of France (Philippe de France). Upon his death, his son inherited but as only a Petit-Fils de France (Grandson of France via Louis XIII) he had to revert to the surname of Orléans. Philippe I de France was addressed as Royal Highness (Son Altesse royale) as was his son Philippe II. Philippe I was also known as Monsieur at his brothers court. At the death of Philippe II, his son Louis d'Orléans took the title and took on the style of Serene Highness as the head of the cadet branch of the House of Bourbon. His son and grandson would take on the style on their successions. After 1709, the Orléans branch of the House of Bourbon were the First Princes of the Blood - this meant that the dukes could be addressed as Monsieur le Prince and that, should there be no possilble heirs to the throne of France, then the Orléans family could claim it.

Name Portrait Lifespan Parents

Philippe I
1660–1701 September 21, 1640 -
June 8, 1701 Louis XIII of France
Infanta Ana of Spain

Philippe II
1701–1723 August 2, 1674 -
December 2, 1723 Philippe I, Duke of Orléans
Elizabeth Charlotte of the Palatinate

Louis
1723–1752 August 4, 1703 -
February 4, 1752 Philippe II, Duke of Orléans
Françoise-Marie de Bourbon

Louis Philippe I
1752–1785 May 12, 1725 -
November 18, 1785 Louis, Duke of Orléans
Margravine Auguste Marie Johanna of Baden-Baden

Louis Philippe II
1785–1793 April 13, 1747 -
November 6, 1793 Louis Philippe I, Duke of Orléans
Louise Henriette de Bourbon

Louis Philippe III
1793–1830 6 October 1773 -
August 26, 1850 Louis Philippe II, Duke of Orléans
Louise Marie Adélaïde de Bourbon

Ferdinand Philippe
1830–1842 September 3, 1810 -
July 13, 1842 Louis Philippe III, Duke of Orléans
Princess Maria Amalia Teresa of the Two Sicilies

Philippe
1842–1869
(did not use the title) 24 August 1838 –
8 September 1894 Ferdinand Philippe, Duke of Orléans
Duchess Helen of Mecklenburg-Schwerin

Philippe
1869–1926 August 24, 1869 -
March 28, 1926 Philippe, Count of Paris
Princess Marie Isabelle of Orléans