The decline of the Habsburg dynasty is one of the most famous cases of royal inbreeding in history. The dynasty traced its roots to the Middle Ages and extended its influence across Europe until the early 20th century. Some famous names in European history were Habsburgs, like Marie Antoinette, the French queen who was executed in the French Revolution, and Archduke Franz Ferdinand, whose death triggered the beginning of World War I. The power of the Habsburg dynasty reached its peak in the 16th and 17th centuries. The Spanish and Austrian lines of the dynasty dominated Europe and intermarried with one another and kept their bloodlines pure. Cousins married each other and uncles married nieces. It is very difficult for the modern observer to keep a track of who was related to whom and how they were related to each other because of the inbreeding in the dynasty. This inbreeding ultimately caused physical and mental illnesses, which resulted in infertility on what can only be described as a royal scale. The inbreeding ultimately caused the decline of the dynasty.
The beginnings of the dynasty
The Habsburg Dynasty is believed to have been founded by Rudolf I, who became the King of Germany in 1273. He was a member of the Habsburg family which had existed since the 11th century. When he was elected king, he brought together large German lands under the control of a single leader. He seized Austria in 1276. In 1281, he gave Austria to his son, Albert. From that moment, Austria and the Habsburg dynasty were linked to each other. The dynasty also added Bohemia and Hungary to its expanding empire and continued to acquire land and power for centuries through both military power and diplomacy.
When Maximilian I, who was the son of the Holy Roman Emperor Frederick III, married Mary, who was the daughter of French King Charles the Bold in 1477, the Habsburgs expanded their European leverage greatly. The marriage caused Maximilian, who later became Holy Roman Emperor, to gain control of the Netherlands, Luxembourg, and parts of France. He later married Bianca, daughter of the Duke of Milan, after Mary’s death. Mary’s death resulted in various issues for Maximilian who had to fight wars to maintain control over the Netherlands, which he had gained through his marriage to her. He also struggled to maintain control of Hungary and by the time of his death in 1518, he had lost influence in Switzerland. Maximilian’s greatest contribution to the Habsburg dynasty was the marriage of his son Philip to Joann of Castile. Joann who was also known as Joan the Mad was the daughter of Ferdinand and Isabella of Spain and brought a lot of wealth and prestige with her. The royal families which were infiltrated by the Habsburgs and the vast lands which they brought under their control, directly led to the inbreeding that ultimately destroyed the family.
Philip of Austria and Joann of Castile
Maximilian’s son Philip married Joann of Castile in 1496. When she inherited Castile after her mother’s death in 1504, her father acted as her regent. By 1506, Philip was vying for control and negotiated a treaty with Ferdinand to give Castile completely to Joann. Due to claims of his wife being mentally ill, Philip took complete control over Castile thereby linking the Spanish and Austrian royal houses through the Habsburg dynasty. Joann, who knew that many people considered her mad, had denied that she was insane. She thought that she only had an issue of jealousy which she had probably inherited from her mother. However, it is unclear whether she actually suffered from any psychological ailments or was a victim of political maneuvering. As she was the child of a marriage between second cousins, this may have caused the psychological disorder which she had. Historians have speculated that Joann may have suffered from depression or bipolar disorder. It may be that her illness was exaggerated by her husband and father for their own gains. Philip lived for only a few months after he declared Joann ineligible to hold the crown of Castile. After his death, Ferdinand retook control and had Joann imprisoned which might have caused her mental health to fail. After Ferdinand died in 1517, Joann’s son Charles who later became Holy Roman Emperor Charles V, inherited Castile and her other Spanish possessions.
Marriages of Uncles to Nieces
In the early 16th century, Habsburg marriages created a dynasty that ruled over most of Western Europe and also explored the New World i.e., the Americas. Charles I of Spain became the Holy Roman Emperor Charles V while his sister Isabella married into the royal family of Denmark and his brother Ferdinand, who also later became the Holy Roman Emperor, married Anne of Bohemia and Hungary. The Habsburgs, despite their massive reach, had difficulty in arranging marriages to maintain their power. Charles V’s daughter, Maria of Spain married her cousin Maximilian who was the son of Ferdinand and Anne in 1548. Charles V’s son, Philip married Anna of Austria, who was the daughter of Maria and Maximilian and his niece. Keeping bloodlines connected was ideal for dynastic power although such marriages led to very close links in terms of kinship. However, the marriage of cousins wasn’t new or considered scandalous. In the 12th century, Eleanor of Aquitaine had married her fourth cousin, Louis VII of France, before she married Henry II of England. Louis VII married his second cousin, Constance. Henry VIII had married many of his relatives, and Isabella and Ferdinand of Spain were his second cousins.
Close connections of dynastic marriages within the Habsburg family became difficult from a genetic perspective in the 16th century, although it wasn’t known at the time. Though the Roman Catholic Church had bans on consanguinity of the same bloodlines in marriage, the Pope could and very often did, allow royal families to get married even though they were consanguineous. As uncles married nieces in the Habsburg dynasty, the family loops became more tightly interconnected. Philip II of Spain married Anne of Austria in 1570 and Charles II of Austria married Maria Anna of Bavaria in 1571. The children of these two marriages, Philip III and Margarita of Austria married each other.
Charles II of Spain
The more the Habsburgs married amongst themselves the more incestuous their marriages became. Philip III of Spain and Margarita of Austria, who were the children of two uncle-niece couples, had two children, who both married their relatives. Their daughter, Maria Anna of Spain, married the Holy Roman Emperor Ferdinand III in 1631, and their son, Philip IV, married his sister’s daughter, Mariana of Austria, who was his niece and cousin many times over. Charles II of Spain was born to them in 1661. He was his own cousin. One of his grandmothers was also his aunt, while the other grandmother was also his great-grandmother. All of his great-grandparents were descended from the same couple, i.e., Philip I and Joann. Charles II was infertile and had a very large tongue which prevented him from speaking. He also had a pointed jaw which was bigger than his teeth. He was also unable to walk till he had fully grown up, by which time he had great difficulty in walking and used to fall regularly. He was the last ruler of Habsburg Spain. The Austrian Habsburg line however continued. Charles II marked the end of the dominance of the Habsburg dynasty.
The Holy Roman Empire
The Holy Roman Empire was neither Holy nor Roman. Rather it was Habsburg. The Austrian Habsburgs held the position of Holy Roman Emperor from the 15th century to the early 19th. Even after Charles V of Spain gave up the title in 1556, the connections between Spanish and Austrian Habsburgs to the role remained very strong. Habsburg supremacy of the title ‘Holy Roman Emperor’ shows the great grasp of the dynasty, which was achieved through endogamy and breeding. The Holy Roman Emperor Charles VI held the following titles, all achieved through centuries of consanguineous marriage and breeding: King of Germany, King of Bohemia, King of Hungary, King of Croatia, Archduke of Austria, King of Naples, King of Sicily, King of Sardinia, Duke of Luxembourg, Duke of Teschen, Duke of Parma and Piacenza and the Count of Flanders. This gives an idea of the power and heft which the dynasty enjoyed.
Infant and child mortality
Infant and child mortality was very high in the Spanish branch of the Habsburg dynasty. From 1527 to 1661, when Philip II and Charles II were born respectively, the Spanish royal families had 34 children, of whom 10 (29.4%) died before 1 year, and 17 (50.0%) died before 10 years. This was caused due to intermarriage and inbreeding. The inbreeding coefficient grew over time. Very little fresh blood entered the family line, making serious health problems certain. Charles II was the peak of Habsburg inbreeding and how it affected the continuance of the family line. His parents, Philip IV and Mariana of Austria had five children, only two of whom survived until maturity. When Charles was born in 1661, he was the only surviving child. Charles II married twice but was unable to produce a child in both of his marriages.
The Habsburg lines of marriage created more medical problems with time. Speculation about Joann the Mad and her mental condition was linked to the fact that her parents were cousins. With Charles II, the Habsburgs created a mid-17th century ‘imbecile’. There has also been speculation about which rulers in the dynasty suffered mental illnesses. The focus is on the Holy Roman Emperor Rudolf II. He was born in 1552 and the grandson of Joann the Mad of Spain. His bouts of depression severely hindered his political authority. He was thus forced to cede power to his brother and retained his title of Holy Roman Emperor in name only.
The Habsburgs were known for their distinctive physical features. The Habsburg jaw, the Habsburg lip, and the Habsburg chin were prominent in the dynasty by the 17th century. When Charles II was born, he was said to have such a big tongue that he salivated constantly, and his bottom jaw was so protruded that he could not even match his teeth to chew. The misshaped head that characterized the Habsburg rulers included a disfigured nose and sagging eyelids. Prognathism, the modern medical definition for the famous Habsburg jaw, was present in art and coinage depicting Habsburgs for many centuries. There are remains of the deformity in Europe in the 21st century.