Marriages in the family

Royal marriages between cousins

Among the 116 marriages recorded in this royal volume, seven joined people who already shared an ancestor: four between first cousins — from Mary, Queen of Scots and Lord Darnley to Victoria and Albert — and three between more distant kin.

1. 1429 — Richard of York and Cecily Neville: second cousins, through King Edward III and Philippa of Hainault
2. 1486 — King Henry VII and Elizabeth of York: third cousins, through John of Gaunt and Katherine Swynford
3. 1565 — Henry Stuart, Lord Darnley and Mary Queen of Scots: first cousins, through Margaret Tudor
4. 1677 — King William III and Queen Mary II: first cousins, through King Charles I and Henrietta Maria of France
5. 1795 — King George IV and Caroline of Brunswick: first cousins, through Frederick Prince of Wales and Augusta of Saxe-Gotha
6. 1840 — Albert of Saxe-Coburg and Gotha and Queen Victoria: first cousins, through Francis of Saxe-Coburg-Saalfeld and Augusta Reuss of Ebersdorf
7. 1947 — Philip Mountbatten and Queen Elizabeth II: second cousins once removed, through Christian IX of Denmark and Louise of Hesse-Kassel

The count is the archive’s, not history’s: a marriage appears here only when both partners’ lines climb to a shared ancestor the volume actually holds, so unions between relatives whose forebears are missing go unrecorded. Within those limits, the seven recorded matches run from 1429 to 1947. Four were first cousins, each partner standing two generations below a common grandparent. The other three sat further out: Richard, Duke of York and Cecily Neville as second cousins, their granddaughter Elizabeth of York and Henry VII as third cousins, and Elizabeth II and Prince Philip as second cousins once removed.

Three of the first-cousin marriages came with reasons beyond the family. Mary, Queen of Scots and Lord Darnley shared a single grandmother, Margaret Tudor, through her two husbands — Darnley’s Wikipedia biography calls him a half-first cousin — and together they stood close to the English succession; the papal dispensation arrived only after the wedding. William of Orange married Mary, daughter of his uncle James, in the middle of a war with France. The future George IV took Caroline of Brunswick, his father’s niece, as the price of the king’s help with his debts. Victoria and Albert shared grandparents in Francis of Saxe-Coburg-Saalfeld and Augusta Reuss.

The two fifteenth-century matches belong to one story. Richard of York and Cecily Neville both descended from Edward III — he through Edmund of Langley, she through John of Gaunt and his daughter Joan Beaufort. Richard was a ward of Cecily’s father, who betrothed the two children in 1424. Their son Edward IV fathered Elizabeth of York, and when she married Henry VII in 1486 the couple were both great-great-grandchildren of John of Gaunt and Katherine Swynford, and fourth cousins through Edward III besides; the marriage needed a papal dispensation. Elizabeth II and Philip were also related by two routes: second cousins once removed through Christian IX of Denmark, and third cousins through Victoria and Albert.

Computed from every recorded line in The British Royal Line on Kinlight; written 29 September 2026.