
Charles II of Spain, the last Spanish Habsburg ruler of Luxembourg, with his Habsburg jaw. / © Public domain
RTL Today contributor Thomas Tutton continues his series on the Dukes and Duchesses of Luxembourg, focusing on the Spanish rulers in the period between 1506 and 1684.
As we've mentioned before, the male Burgundian line ended in 1477, and with Mary I's death in 1482, the Duchy of Luxembourg fell to the four-year-old Philip II.
This would eventually result in Luxembourg becoming ruled by the sovereigns of Spain for almost two centuries. Who were the Spanish Dukes and Duchesses of Luxembourg? And were they really inbred? (The answer is yes.)
Listen to this and other topics – like what the Austrian Habsburg branch was up to – right below, or feel free to keep reading.
The sad story of Joanna the Mad
Philip II's father, Maximilian of the Habsburg dynasty, was appointed regent of the Burgundian Netherlands but left most of the region's administration to a governor-general. Governors in Luxembourg handled internal affairs, beginning a tradition where Habsburg rulers of Luxembourg rarely visited the duchy.
In 1496, the grown-up Philip, known as the Handsome, married Joanna, the third child of Ferdinand of Aragon and Isabelle of Castile, who had united Spain and driven out the last Moorish kingdom in 1492. This was not initially a promising match – but then Joanna’s mother, brother, sister and nephew all died in the space of seven years, leaving her Queen of Castile and the heiress to virtually the whole of Spain.
Joanna faced further misfortune when Philip II died in 1506, reportedly poisoned by her father, Ferdinand, who declared her insane and imprisoned her while she insisted on staying with her husband's corpse. Their son Charles, known as Charles V, kept her locked up for forty years until she passed away in 1555, earning her the tragic moniker "Joanna the Mad."

Joanna of Castile, better known as Joanna the Mad. / © Public domain
Charles V, emperor of basically everything
Charles V emerged as a pivotal figure in European history. Known as the Duke of Luxembourg in his early years, he amassed numerous titles following his father's death in 1506, inheriting the Low Countries and Luxembourg. From his maternal grandfather in 1516, he inherited the crowns of Aragon and Castile, gaining control over Spain, Naples, Sicily, and Sardinia.
Following his paternal grandfather Maximilian's death in 1519, Charles took over most of Austria, Bohemia, and Hungary. To top it all off, Charles was elected King of Germany in 1519 and crowned Holy Roman Emperor in 1530.

Charles V was the ruler of Luxembourg (and quite a few other places) from 1506-1556. / © Public domain
He was a busy man, but Charles visited Luxembourg multiple times, notably inspecting the fortress in 1541. In 1549, he issued the Pragmatic Sanction, unifying the seventeen provinces of the old Burgundian Netherlands while preserving their unique customs. Luxembourg would remain within the framework of the Habsburg Netherlands for the next 250 years.
Ruling one of the largest Empires in European history proved rather exhausting for Charles, and he didn’t want his successors to have to face such a heavy workload. He therefore split his dominions: his brother Ferdinand received the Habsburg lands in Austria and succeeded him as Holy Roman Emperor, while his son Philippe inherited Spain, parts of Italy, and the Netherlands, including Luxembourg.
This seemed a great idea, but it would have some bad, bad consequences.
Isabella Clara Eugenia
The Spanish Habsburgs' rule over Luxembourg was problematic. Philippe II of Spain, known as Philippe III in Luxembourg, faced numerous failures, including the bloody Dutch revolt and the unsuccessful Great Armada invasion of England. One of the more interesting sovereigns of the Spanish line was Isabella Clara Eugenia, the daughter of Philip, himself the son of Charles V.
Isabella had been so close to her father that he actually ceded the remaining provinces of the Netherlands, including Luxembourg, to her on the condition that she marry her cousin Albert, Archduke of Austria.

Isabella Clara Eugenia was one of the more popular Spanish Habsburgs in Luxembourg. / © Public domain
Their reign was popular and sometimes remembered as the Golden Age of the Spanish Netherlands, with art flourishing and a measure of peace returning.
When Albert died, Luxembourg reverted to Spanish control under Philippe IV, who engaged in extensive conflict with France, leading to Luxembourg's partition in 1659. He was content to leave Isabella Clara Eugenia in charge as Governor of the provinces until her death in 1633.
End of the Spanish rulers
Philip IV of Spain, like his grandfather Philip II of Spain, spent most of his rule dedicating himself to fighting the French, with serious consequences for the Duchy of Luxembourg, which suffered its first partition in 1659.
Philippe IV was succeeded by Charles II, or Charles IV of Luxembourg, in 1665. The Habsburgs' policy of intermarriage, intended to preserve their dynasty, led to severe health issues among their descendants.
The Spanish and Austrian branches, all cousins originally, intermarried heavily, resulting in horrendous health issues for their descendants.
Charles V was the first to show these signs, suffering from epilepsy and the infamous Habsburg jaw deformity. Philippe IV married his niece Mariana, making Charles II his great-uncle and first cousin. Charles II's health was frail, and his deformed jaw made eating and speaking difficult. His jaw was so deformed that he could barely eat or speak, and he suffered from chronic ill health throughout his life, to the extent that it was considered a miracle that he survived until the age of 40.
His reign ended with Luxembourg falling to Louis XIV's French troops in 1684, and his death in 1700 sparked the War of the Spanish Succession. The death of Charles II would provoke the War of the Spanish Succession, ending Spanish Habsburg rule over Luxembourg, but it had in practice already ended with Louis XIV’s successful capture of the fortress in 1684.

Here's poor old Charles II of Spain again. / © Public domain
Horrifyingly, in 2009, a team of Spanish geneticists led by Gonzalo Alvarez concluded that due to the cumulative effects of generations of inbreeding, Charles II was more inbred than the child of a brother and sister. Let that sink in for a second.
Overall, the two centuries of Spanish rule are usually considered disastrous for Luxembourg – and they were disastrous for the Habsburg family as well.
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