Charles II of Spain died in 1700 unable to chew his own food, the last king of a dynasty that had spent two centuries marrying itself. His inbreeding coefficient matched that of a child born to a brother and sister. He was not the product of siblings. He was the product of a rule the Habsburgs could have written, and chose not to.
This video asks a single question. What if, somewhere near the start, the Habsburgs had banned the close marriages? Not because anyone in the sixteenth century understood genetics, but because a pope leaned on them or a bishop lost his nerve over the endless dispensations. The answer is stranger than the comforting one, because some of the crowns the family wore only fit because of exactly the weddings you would have to cancel.
Trace the line and the pattern is hard to miss. Maximilian I married Mary of Burgundy and won the Low Countries. Charles V married his first cousin Isabella of Portugal. Philip II married his niece Anna of Austria. Philip IV married his niece Mariana of Austria, and that union produced Charles II. A 2009 study that rebuilt a pedigree of more than three thousand people found that nine of the eleven marriages in the main Spanish line were between third cousins or closer, close to 82 percent. The inbreeding coefficient climbed from about 0.025 in Philip I to 0.254 in Charles II.
The cost showed up in the nursery. Of thirty-four children born into these families between 1527 and 1661, ten died before their first birthday and seventeen before the age of ten. Half were gone before adolescence, in the best-fed households in Spain. The famous Habsburg jaw grew more pronounced as the pedigree tightened, according to a 2019 study of sixty-six royal portraits, though the chin was only a symptom riding along, never the cause.
Then the counterfactual. Cancel the 1526 wedding of Charles V and Isabella and Philip II is never born, and every Spanish Habsburg king after him vanishes with him. No Portuguese claim in 1580, so Spain likely never absorbs Portugal. No frail childless king in 1700, so no War of the Spanish Succession, no Bourbon Madrid, no British Gibraltar in 1713. What you never get is a bigger Habsburg empire. The marriages that poisoned the bloodline were the same glue holding the family's map together.
TIMESTAMPS:
0:00 - The Most Inbred King in European History
1:00 - Charles II of Spain, the Dying King of 1700
1:41 - How the Habsburgs Won Empires Through Marriage
2:31 - Charles V and the Largest Inheritance Since Rome
3:08 - Why Spain and Austria Married Each Other
3:55 - The Cousin Marriages of Philip II
4:29 - Uncle Marries Niece, the Birth of Charles II
5:23 - The 2009 Study, 82% Married Third Cousins or Closer
6:22 - The Inbreeding Coefficient of 0.254 Explained
7:18 - Half the Royal Children Died Before Age Ten
8:38 - The Habsburg Jaw, What the Portraits Reveal
9:40 - Why One Cousin Marriage Is Not a Death Sentence
10:09 - The What-If, Banning the Cousin Marriages
13:27 - 1580, How Spain Nearly Swallowed Portugal
15:28 - The Empty Cradle and the War of the Spanish Succession
16:56 - Gibraltar, Britain, and the 1713 Peace of Utrecht
19:31 - What Would Have Happened Anyway
20:54 - What the Cousin Marriages Actually Bought Them
READ MORE:
https://theforgottenhistory.com/journal/what-if-the-habsburgs-had-never-practiced-cousin-marriage-across-generationsSOURCES & FURTHER READING:
https://pubmed.ncbi.nlm.nih.gov/19367331/https://pmc.ncbi.nlm.nih.gov/articles/PMC2664480/https://www.britannica.com/biography/Charles-II-king-of-Spainhttps://www.britannica.com/event/War-of-the-Spanish-Successionhttps://www.britannica.com/topic/House-of-Habsburg-royal-dynastyABOUT THIS VIDEO:
This video is about the Habsburg dynasty, Charles II of Spain, and the two centuries of cousin and uncle-niece marriages that ended it. Key figures include Charles V, Isabella of Portugal, Philip II, Anna of Austria, Philip IV, Mariana of Austria, Maximilian I, Mary of Burgundy, Joanna of Castile, and Louis XIV. Key events and terms include the 2009 Alvarez pedigree study, an inbreeding coefficient of 0.254, the 1580 Iberian Union, the War of the Spanish Succession, the 1713 Peace of Utrecht, Gibraltar, the asiento, the Habsburg jaw, the Bourbon succession, Madrid, Vienna, and the sixteenth to eighteenth centuries.
#Habsburg #CharlesIIofSpain #HabsburgJaw #SpanishHistory #PhilipII #WarOfTheSpanishSuccession #Inbreeding #EuropeanHistory #Counterfactual #DynastyHistory #HistoryDebunked