Ferdinand II of Aragon's marriage to Isabella I of Castile produced seven children, five of whom survived birth and lived to adulthood. They arranged strategic political marriages for all of these children to powerful monarchs and well-connected women. Although several bloodlines were cut short and the rest initially intermarried to form a close-knit group centered around the House of Habsburg, this group became the most powerful family in Europe. Within only six generations of the Catholic Monarchs their offspring ruled in the Holy Roman Empire, the Kingdom of France, the Kingdom of Spain, the Kingdom of England, the Kingdom of Portugal (before, during and after the Iberian Union), the Archduchy of Austria with the Kingdom of Bohemia and the Kingdom of Hungary in personal union, the Kingdom of Poland with the Grand Duchy of Lithuania in personal union, Electorate of Brandenburg with the Duchy of Prussia in personal union, the Electorate of Saxony, the Duchy of Mantua, the Duchy of Montferrat, the Duchy of Parma, the Duchy of Lorraine and others.

Among the living descendants of Isabella I and Ferdinand II are all of the current European monarchs from hereditary monarchies (i.e. not Andorra and Vatican City). Felipe VI of Spain and Henri of Luxembourg are both descended in the male line from Philip V of Spain, whose grandmother Maria Theresa of Spain was a male-line descendant of Ferdinand and Isabella's daughter Joanna the Mad. Many other paths are possible to find due to interbreeding. Philippe of Belgium is also a descendant multiple times over. One such path goes through Leopold III of Belgium, Miguel I of Portugal and Charles IV of Spain back to Philip V again. Although the Protestant Reformation divided Europe in half in terms of royal intermarriage, through the children of Maria of Austria, Duchess Consort of Jülich-Cleves-Berg the bloodline also entered the Protestant noble houses and can therefore be traced to Britain, Scandinavia and the Netherlands. The most common line passes through Maria's great-great-granddaughter Princess Elisabeth Sophie of Saxe-Altenburg.

Some British lines descend from Henrietta Maria of France, granddaughter of Joanna of Austria, Grand Duchess of Tuscany. Although her legitimate descendants in Britain were banished during the Glorious Revolution, many remain descending from the bastard children of Charles II and James VII. Princess Diana was and her sons and grandchildren are among this group by virtue of descent from Henry FitzRoy, 1st Duke of Grafton and Henrietta FitzJames. Queen Camilla is also in this group by descent from Anne Lennox, Countess Consort of Albemarle.

Charles III of the United Kingdom as well as every monarch of Britain since George III are descendants. George III's mother was Princess Augusta of Saxe-Gotha, a great-granddaughter of Elisabeth Sophie. Margrethe II of Denmark and Carl XVI Gustaf of Sweden share as their grandmother Princess Margaret of Connaught, a granddaughter of Queen Victoria, herself granddaughter to George III. Harald V of Norway's grandmother was Maud of Wales, another granddaughter of Victoria. A different line from Maria of Austria passes through Duchess Sophie of Prussia and her great-great-grandson William IV, Prince of Orange, whose grandson was elevated in rank to become William I of the Netherlands. Willem-Alexander of the Netherlands is his descendant, although not in the male line, but through a series of three queens-regnant of the Netherlands.

The two princes Albert II of Monaco and Hans-Adam II of Liechtenstein also have this blood. Albert's was introduced to the Grimaldi family by Lady Mary Victoria Douglas-Hamilton, granddaughter of Charles, Grand Duke of Baden. Charles was, among other ways this descent can be traced, a double great-grandson of Louis VIII, Landgrave of Hesse-Darmstadt, a great-grandson of Elisabeth Sophie. Hans-Adam has the bloodline from his grandmother Archduchess Elisabeth Amalie of Austria, who was both a Habsburg with near male-line descent (excluding Maria Theresa and Joanna the Mad) and a granddaughter of Miguel I of Portugal mentioned above as an ancestor of Philippe of Belgium.

Children ImageNameBirthDeathFamilyInfanta Isabella of Aragon2 Oct 147023 Aug 1498Married 1490, Afonso, Prince of Portugal, no issue. Married 1497, Manuel I, King of Portugal, had issue.John, Prince of Asturias30 Jun 14784 Oct 1497Married 1497, Margaret of Austria, no issue.Joanna I, Queen of Castile and Aragon6 Nov 147912 Apr 1555Married 1496, Philip IV, Duke of Burgundy, had issue.Maria of Aragon, Queen of Portugal29 Jun 14827 Mar 1517Married 1500, Manuel I, King of Portugal, had issue.Catherine of Aragon, Queen of England16 Dec 14857 Jan 15361. Married 1501, Arthur, Prince of Wales, no issue. 2. Married 1509, Henry VIII, King of England, had issue.

Grandchildren

Children of Isabella of Aragon, Queen of Portugal Isabella of Aragon first married in 1490 Afonso, Hereditary Prince of Portugal, who died the next year following a fall from his horse. She married his cousin Manuel I of Portugal, known as 'the fortunate' in 1497. Together, they had one son. She died within an hour after her son's birth. ImageNameBirthDeathFamilyMiguel da Paz, Prince of Portugal23 August 149819 July 1500Died in infancy.

Children of Joanna I of Castille Joanna I of Castille, later known as Joanna the Mad, married Philip the Handsome in 1496.Bethany Aram, Juana the Mad: Sovereignty and Dynasty in Renaissance Europe (Baltimore, Johns Hopkins UP, 2005), p. 37 At the time of the marriage, she was third in line to the throne behind her brother and older sister Isabella. Following the death of both, Joanna became heir. ImageNameBirthDeathFamilyEleanor of Austria, Queen of Portugal15 November 149825 February 1558Married 1518, Manuel I of Portugal, had two children. Married 1530, Francis I of France, no issue.Charles V, Holy Roman Emperor24 February 150021 September 1558Married 1526, Isabella of Portugal, had issue. Charles also had several illegitimate children including;

Margaret of Parma (1522–1586) Joanna of Austria (1522–1530) Tadea della Penna (1523 – c. 1562) Cornelis de Hooghe (1541–1583), Dutch cartographer John of Austria (1547–1578)Isabella of Austria, Queen of Denmark, Norway, and Sweden18 July 150119 January 1526Married 1514, Christian II of Denmark, had issue.Ferdinand I, Holy Roman Emperor10 March 150325 July 1564Married 1521, Anne of Bohemia and Hungary and had issue.Mary of Austria, Queen of Hungary15 September 150518 October 1558Married 1515, Louis II of Hungary, had no issue.Catherine of Austria, Queen of Portugal14 January 150712 February 1578Married 1529, John III of Portugal and had issue.

Children of Maria of Aragon, Queen consort of Portugal Maria of Aragon married Manuel I of Portugal in 1500, the widower of her older sister Isabella. ImageNameBirthDeathFamilyJohn III of Portugal6 June 150211 June 1557Married 1525, Catherine of Austria (Daughter of Joanna I and Philip the Handsome) and had issue. John III also had an illegitimate child;

Duarte, Archbishop of Braga (1529 - 11 November 1543)Isabella of Portugal, Holy Roman Empress24 October 15031 May 1539Married 1526, Charles V, Holy Roman Emperor, had issue.Beatrice of Portugal, Duchess of Savoy31 December 15048 January 1538Married 1504 Charles III, Duke of Savoy, had issue.Luís of Portugal, Duke of Beja3 March 150627 November 1555Never married, but had an illegitimate son António, Prior of Crato, who was claimant to the Portuguese throne.Infante Ferdinand, Duke of Guarda5 June 15077 November 1534Married Guiomar Coutinho, 5th Countess of Marialva and 3rd Countess of Loulé. They had two children. Luisa (1531 - October 1534) and a son (born 1 August 1533) who died shortly after birth.Cardinal-Infante Afonso of Portugal23 April 150921 April 1540Infanta Maria15111513Died young.Henry, Cardinal-King of Portugal31 January 151231 January 1580Upon inheriting the Kingdom of Portugal, Henry sought to be released from his vows so that he might marry and continue the House of Aviz. Pope Gregory XIII did not allow this, not wanting to antagonise Philip II of Spain, his successor.Duarte, Duke of Guimarães7 October 151520 September 1540Married 1537 Isabel of Braganza and had issue.Infante António8 September 15161 November 1516Died in infancy.

Children of Catherine of Aragon, Queen consort of England Catherine of Aragon first married Arthur, Prince of Wales in 1501, though he died the following year. She married his brother Henry VIII of England in 1509 and had issue. Due to her perceived inability to give the King a surviving son, the marriage was annulled in 1533. ImageNameBirthDeathFamilyHenry, Duke of Cornwall1 January 151122 February 1511Died suddenly, with no recorded cause of death.Mary I of England18 February 151617 November 1558Married her cousin Philip II of Spain in 1554, but had no issue.

Great-Grandchildren

Children of Eleanor of Austria, Queen consort of Portugal and France Eleanor of Austria married first Manuel I of Portugal in 1518, the widower of two of her aunts, Isabella and Maria of Aragon. They had two children. Following the death of her husband, Eleanor remarried in 1530 to Francis I of France, he often ignored her and as such, the marriage remained childless. ImageNameBirthDeathFamilyInfante Charles18 February 152015 April 1521Died in infancy.Maria, Duchess of Viseu18 June 152110 October 1577Never married and had no issue.

Children of Charles V, Holy Roman Emperor and Isabella of Portugal Charles V married his first cousin Isabella of Portugal, daughter of Manuel I of Portugal and Maria of Aragon, in 1526. The marriage is regarded as a happy one,Kamen, H. (1997). Philip of Spain. Yale University Press. p. 2. . the couple had five surviving children. ImageNameBirthDeathFamilyPhilip II of Spain21 May 152713 September 1598Married Maria Manuela, Princess of Portugal, his double first cousin, in 1543. They had one son.

Carlos, Prince of Asturias (8 July 1545 – 24 July 1568), no issue.

Married Mary I of England in 1554. She was his first cousin once removed, as daughter of Catherine of Aragon (see above). They had no issue.

Married 1559 Elisabeth of Valois, and had issue.

Isabella Clara Eugenia, Lady of the Netherlands (12 August 1566 – 1 December 1633), no issue. Catherine Michaela of Austria (10 October 1567 – 6 November 1597), married and had issue. Joan (born and died 3 October 1568)

Married 1570 his niece, Anna of Austria, and had issue.

Ferdinand, Prince of Asturias (4 December 1571 – 18 October 1578), died in childhood. Carlos Lorenzo (12 August 1573 – 30 June 1575), died in infancy. Diego, Prince of Asturias (15 August 1575 – 21 November 1582), died in childhood. Philip III of Spain (3 April 1578 – 31 March 1621), married and had issue. Maria (14 February 1580 – 5 August 1583)Maria of Austria, Holy Roman Empress21 June 152826 February 1603Married 1548 her first cousin Maximilian II, Holy Roman Emperor, and had issue.

Anna of Austria, Queen of Spain (1 November 1549 – 26 October 1580), married and had issue (see above). Ferdinand (28 March 1551 – 25 June 1552), died in infancy. Rudolf II, Holy Roman Emperor (18 July 1552 – 20 January 1612), had illegitimate issue. Archduke Ernest of Austria (15 July 1553 – 12 February 1595), no issue. Elisabeth of Austria, Queen of France (5 July 1554 – 22 January 1592), married without issue. Marie (27 July 1555 – 25 June 1556), died in infancy. Matthias, Holy Roman Emperor (24 February 1557 – 20 March 1619), married without issue. Maximilian III, Archduke of Austria (12 October 1558 – 2 November 1618), no issue. Albert VII, Archduke of Austria (13 November 1559 – 13 July 1621), married without issue. Archduke Wenceslaus of Austria (9 March 1561 – 22 September 1578), no issue. Frederick (21 June 1562 – 16 January 1563), died in infancy. Marie (19 February 1564 – 26 March 1564), died in infancy.