European Marital Alliances

Chapter 1: 1460s - 1490s

The alliance formed by England and the kingdoms of Aragon and Castile by the betrothal of Katharine of Aragon to Arthur Prince of Wales in 1489 was only one of a series of marital alliances across Europe.

It had been the case for hundreds of years that the marriage of royalty was part of the diplomatic process. Such marriages were supposed to promote peace and understanding between the countries of the respective bride and groom. Unfortunately, for many women who left their homes and families, the result was that their loyalties were divided as their husbands and sons became involved in conflicts with their country of origin. It is helpful when considering any alliances or wars, to look at the family relationships involved.

Because European royalty was heavily interrelated, the problem of 'consanguinity' or 'affinity' frequently arose. This was exacerbated after the Reformation, when the pool of available spouses became smaller as Catholic and Protestant countries tended to intermarry within their religious group. Consanguinity was a blood relationship, whilst affinity was a relationship through marriage.

Whilst the people of the time were completely unaware of the genetic reasons for close intermarriage to produce unhealthy offspring, it was forbidden both in the Bible and in canon law. Since the medical implications were not understood, it was believed that if the Pope were to grant a dispensation for marriages within the forbidden degrees of relationship to take place, that would be sufficient for the parties to be absolved of any sin. It was not, of course, going to make any difference to the genetic outcome, and repeated inter marriages between the Portuguese and Spanish royal houses, and then the Spanish and Austrian branches of the House of Hapsburg resulted in a sickly race that eventually died out.

Listed below are some of the key marriages that affected European politics. We have started in 1469 because the marriage that took place in that year was pivotal to the unfolding of 16 th century European history. As many Christian names recur we have tried to use a variety of English and native spellings to try to differentiate between individuals. The names/titles that the individuals had in their family of origin either at birth or by inheritance are in plain text, their later titles in bold.


On 19 October 1469, Isabella, half-sister of Enrique (Henry) IV of Castile married Ferdinand, heir to the throne of the neighbouring kingdom of Aragon. Isabella, as part of an agreement with Enrique in which he recognised her as his heiress, had promised to ask his consent before marrying. Her decision not to, presumably because she knew he would have forbidden the match, led to him withdrawing his recognition of her as his heir. When Enrique died in 1474, Castile was plunged into a civil war between the supporters of Isabella and Juana ‘La Beltraneja’ who was the daughter of Enrique’s wife but almost certainly not of the King himself.

Ferdinand and Isabella were second cousins as well as having a number of other blood relationships. Their mutual ancestors were Juan I, King of Castile and his wife Leonor (Eleanor) of Aragon. Juan and Leonor’s sons became kings of Castile and Aragon. Thus, a Papal dispensation was needed, which was granted, although not until the couple had already taken their vows.

Ferdinand and Isabella had five children, whose marriages will be dealt with later.

  1. Isabella of Aragon, Queen of Portugal 1470 - 1498
  2. Juan, Prince of the Asturias 1478 - 1497
  3. Juana, Queen of Castile, Duchess of Burgundy (1479 – 1555)
  4. Maria of Aragon, Queen of Portugal (1482 – 1517)
  5. Katharine of Aragon, Princess of Wales, Queen of England (1585 – 1536)


In 1477, Maximilian, Archduke of Austria and King of the Romans married Mary, Duchess of Burgundy.

Maximilian was the son of the Emperor Frederick III, the first from the Hapsburg family to be elected as Emperor. Maximilian’s mother was Eleanor of Portugal, who was the paternal first cousin of Ferdinand of Aragon.

Maximilian married Mary in 1477, shortly after the death of her father, Charles the Bold, Duke of Burgundy. France was trying to reclaim Mary’s territories, on the basis that those parts of the Duchy which were subject to the Crown of France could not be inherited by a woman. While a part of the Duchy had to be ceded to the French crown, Mary and Maximilian retained a significant proportion. Mary died in 1482 after a fall from a horse. She left two children:

  1. Philip the Fair, Archduke of Austria, Duke of Burgundy, King of Castile (1478 – 1506)
  2. Marguerite, Archduchess of Austria, Princess of the Asturias, Duchess of Savoy, Regent of the Netherlands (1480 - 1530)

Maximilian’s second marriage to Bianca Maria of Savoy was childless.


On 18th January 1486 Henry VII of England married Elizabeth of York, daughter of Edward IV of England. The purpose was to bring together the warring branches of the English Royal house. They were third cousins, both being descended from John of Gaunt and his third wife, Katherine de Roet. This required a Papal dispensation, which was granted. The couple had four children who lived to marriageable age:

  1. Arthur, Prince of Wales 1486 - 1502
  2. Margaret, Queen of Scots 1489 - 1541
  3. Henry, Duke of York, King of England 1491 - 1547
  4. Mary, Queen of France, Duchess of Suffolk 1496 - 1533


During the decade of the 1490s a whole series of marriages took place that affected European politics.

First, in 1490 the Infanta Isabella, daughter of Ferdinand and Isabella (see above) married Alfonso, Prince of Portugal. The alliance between Castile and Portugal was essential to the security of Spain. The royal houses had intermarried a number of times already and this Isabella’s grandmother had been a princess of Portugal. Alfonso died in 1491, and Isabella, after a period of intense mourning, was married to Manuel, the next Portuguese heir. Both of Isabella’s husbands were first cousins to her mother. Isabella and Manuel had one child, Miguel, who was, for the short two years of his life, heir to Castile, Aragon and Portugal. Isabella died in childbirth.

Second, on 20th October 1496, the Infanta Juana, daughter of Ferdinand and Isabella married Philip the Fair, Duke of Burgundy (see above). As noted above, Philip’s grandmother was Ferdinand’s cousin, so the couple were second cousins, once removed. A dispensation was again sought and given.This marriage, although deeply unhappy, was extremely successful from a dynastic point of view. They had the following children:

  1. Leonor (Eleanor), Archduchess of Austria, Queen of Portugal, Queen of France (1498 – 1558)
  2. Charles, Archduke of Austria, Duke of Burgundy, King of Spain (Aragon & Castile) Holy Roman Emperor (1500 – 1556)
  3. Isabel, Archduchess of Austria, Queen of Denmark (1501 – 1526)
  4. Ferdinand, Archduke of Austria, King of the Romans, Holy Roman Emperor, King of Hungary & Bohemia (1503 – 1564)
  5. Mary, Archduchess of Austria, Queen of Hungary, Regent of the Netherlands (1505 – 1558)
  6. Catherine, Archduchess of Austria, Queen of Portugal (1507 – 1558)

These six men and women were the most important rulers in Europe until the late 1550s. Their power and influence was challenged only by that of the Kings of France.

So far as relationships with England and Scotland were concerned, the marriage of their aunt, Katharine, to Henry VIII was an important element of the overall Hapsburg strategy of surrounding France. As well as supporting Katharine’s position during the annulment, they extended their support to her daughter, Mary. In particular Mary of Hungary, as Regent of the Netherlands, gave her cousin Mary of England moral support during the reign of Edward VI.

Isabel of Austria’s marriage to Christian of Denmark, who was the cousin of James V of Scots, was another thread in this tapestry.

The other important marriage of the 1490s was that of Anne of Brittany, Duchess of Brittany in her own right and widow of Charles VIII of France, to Charles’ cousin and heir Louis XII. Anne and Louis had two daughters:

  1. Claude of France, Queen of France (1499 – 1524)
  2. Renée of France, Duchess of Ferrara (1510 – 1574)