Like many royal couples, Queen Elizabeth II and Prince Philip are distantly related through their royal ancestors. The practice of marrying within royal bloodlines has become less common as royalty's power is lessened. But so many in the royal family are related to each other, it would have been difficult for Princess Elizabeth to find an unrelated partner. Here's how Britain's longest-reigning queen and her husband, Philip, are related.

Did You Know? Elizabeth and Philip are third cousins through Queen Victoria and are also second cousins once removed through King Christian IX of Denmark.

Background of the Royal Couple

When Elizabeth and Philip were both born, it seemed unlikely that they would one day become the most prominent royal couple in modern history. Princess Elizabeth Alexandra Mary, as Queen Elizabeth was named when she was born in London on April 21, 1926, was third in line for the throne behind both her father George VI and his older brother who would become Edward VIII. Prince Philip of Greece and Denmark didn't even have a country to call home. He and the royal family of Greece were exiled from that nation shortly after his birth in Corfu on June 10, 1921.

Elizabeth and Philip met several times as children. They became romantically involved as young adults while Philip was serving in the British Navy during World War II. The couple announced their engagement in June 1947, and Philip renounced his royal title, converted from Greek Orthodoxy to Anglicanism, and became a British citizen.

He also changed his surname from Battenburg to Mountbatten, honoring his British heritage on his mother's side. Philip was granted the title of Duke of Edinburgh and the style of His Royal Highness on his marriage, by his new father-in-law, George VI.

Queen Victoria Connection

Elizabeth and Philip are third cousins through Queen Victoria of Britain, who ruled from 1837 to 1901; she was their great-great-grandmother.

Philip is descended from Queen Victoria via maternal lines:

Philip's mother was Princess Alice of Battenburg (1885–1969), who was born at Windsor Castle. Princess Alice's husband was Prince Andrew of Greece and Denmark (1882–1944).

Princess Alice's mother was Princess Victoria of Hesse and by Rhine (1863–1950). Princess Victoria was married to Prince Louis of Battenberg (1854–1921).

Princess Victoria of Hesse and by Rhine was the daughter of Princess Alice of the United Kingdom (1843–1878).

Princess Alice's mother was Queen Victoria (1819–1901). She married Prince Albert of Saxe-Coburg and Gotha (1819–1861) in 1840.

Elizabeth is a direct descendant of Queen Victoria through paternal lines:

Elizabeth's father was George VI (1895–1952). He married Elizabeth Bowes-Lyon (1900–2002) in 1925.

George VI's father was George V (1865–1936). He married Mary of Teck (1867–1953) in 1893, a German princess raised in England.

George V's father was Edward VII (1841–1910). He married Alexandra of Denmark (1844–1925), a Danish princess.

Edward VII's mother was Queen Victoria (1819–1901). She married Prince Albert of Saxe-Coburg and Gotha (1819–1861) in 1840.

Connection Through King Christian IX of Denmark

Elizabeth and Philip are also second cousins, once removed, through King Christian IX of Denmark, who ruled from 1863 to 1906.

Prince Philip's father is a descendant of Christian IX:

Prince Andrew of Greece and Denmark was Philip's father. He was married to Princess Alice of Battenburg, listed above.

George I of Greece (1845–1913) was Prince Andrew's father. He married Olga Constantinova of Russia (1851–1926) in 1867.

Christian IX of Denmark (1818–1906) was George I's father. He married Louise of Hesse-Kassel (1817–1898) in 1842.

Queen Elizabeth's father was also a descendant of Christian IX:

George VI, Elizabeth's father, was the son of George V.

George V's mother was Alexandra of Denmark.

Alexandra's father was Christian IX.

Queen Elizabeth's connection to Christian IX comes through her paternal grandfather, George V, whose mother was Alexandra of Denmark. Alexandra's father was King Christian IX.

More Royal Relations

Queen Victoria was related to her husband, Prince Albert, as first cousins and also third cousins once removed. They had a fertile family tree, and many of their children, grandchildren, and great-grandchildren married into other royal families of Europe.

Britain's King Henry VIII (1491–1547) was married six times. All six of his wives could claim descent through Henry's ancestor, Edward I (1239–1307). Two of his wives were royal, and the other four were from the English nobility. King Henry VIII is Elizabeth II's first cousin, 14 times removed.

In the Habsburg royal family, intermarriage among close relatives was very common. Philip II of Spain (1572–1598), for instance, was married four times; three of his wives were related closely to him by blood. The family tree of Sebastian of Portugal (1544–1578) illustrates how intermarried the Habsburgs were: he had only four great-grandparents instead of the usual eight. Manuel I of Portugal (1469–1521) married women who were related to each other; their descendants then intermarried.