Around 645 King Oswiu of Northumbria (age 33) and Eanflæd Queen Consort Bernicia (age 18) were married. She by marriage Queen Consort Bernicia. She the daughter of King Edwin of Northumbria and Æthelburh Oiscingas Queen Consort Northumbria (age 40). He the son of Æthelfrith King Northumbrians and Acha Queen Consort Northumbria. They were half first cousins.

On 02 Dec 1022 Alfonso "Noble" V King Leon (age 28) and Urraca Jiménez Queen Consort Leon were married. She by marriage Queen Consort Leon. She the daughter of García Sánchez "Tremulous" II King Pamplona and Jimena Fernández Bermúdez Queen Consort Pamplona. He the son of Bermudo "Gouty" II King Galicia II King Leon and Elviro Garcia Queen Galicia. They were half first cousins.

In 1088 William "Troubadour" Poitiers IX Duke Aquitaine (age 16) and Ermengarde Anjou Duchess Brittany and Aquitaine (age 20) were married. She by marriage Duchess Aquitaine. She the daughter of Fulk "Réchin" Anjou 4th Count Anjou (age 45) and Hildegarde Beaugency Countess Anjou (age 44). He the son of Guy William Poitiers VIII Duke Aquitaine and Hildegarde Burgundy Duchess Aquitaine (age 32). They were half first cousins.

On 05 Jul 1324 Charles IV King France I King Navarre (age 30) and Joan Évreux Queen Consort France (age 14) were married. She by marriage Queen Consort of France. She the daughter of Louis I Count Évreux and Margaret Artois Countess Évreux. He the son of Philip "The Fair" IV King France and Joan Blois I Queen Navarre. They were half first cousins. He a great x 4 grandson of King Henry "Curtmantle" II of England. She a great x 2 granddaughter of King Henry III of England.

After 20 Jan 1465 Thomas Boyd 1st Earl Arran and Elizabeth Montgomerie (age 26) were married. They were half first cousins.

On 29 Jul 1565 Henry "Lord Darnley" Stewart (age 19) and Mary Queen of Scots (age 22) were married at Holyrood Palace, Holyrood. She the daughter of King James V of Scotland and Mary of Guise Queen Consort Scotland. He the son of Matthew Stewart 4th Earl Lennox (age 48) and Margaret Douglas Countess Lennox (age 49). They were half first cousins. He a great grandson of King Henry VII of England and Ireland. She a great granddaughter of King Henry VII of England and Ireland.

In 1650 Compton Reade 1st Baronet (age 24) and Mary Cornwall Lady Reade (age 20) were married at the Church of St Mary Magdalene, Duns Tew. They were half first cousins.

On 02 May 1655 William Ker 2nd Earl Roxburghe (age 32) and Jane Ker Countess Roxburgh were married. She by marriage Countess Roxburghe. She the daughter of Henry Ker and Margaret Hay Countess Cassilis. He the son of John Drummond 2nd Earl Perth (age 67) and Jean Ker Countess Perth. They were half first cousins.

In or before 1682 Robert Luttrell and Alison or Anne Preston (age 41) were married. They were half first cousins.

Before 09 Mar 1686 Henry Seymour (age 74) and Elizabeth Killigrew (age 73) were married. They were half first cousins.

In or before 1696 Richard Courtenay and Catherine Waller were married. He the son of William Courtenay 5th Earl Devon (age 67) and Margaret Waller Countess Devon. They were half first cousins.

On 04 Aug 1713 James Brydges 1st Duke Chandos (age 40) and Cassandra Willoughby Duchess Chandos (age 43) were married. They were half first cousins.

On 05 Mar 1737 Charles Emmanuel III King Sardinia (age 35) and Elisabeth Therese Lorraine Queen Consort Sardinia (age 25) were married. She by marriage Queen Consort Sardinia. She the daughter of Leopold Duke of Lorraine and Élisabeth Charlotte Bourbon Duchess Lorraine (age 60). He the son of Victor Amadeus King Sardinia and Anne Marie Bourbon Queen Consort Sardinia. They were half first cousins. He a great grandson of King Charles I of England, Scotland and Ireland. She a great x 3 granddaughter of King James I of England and Ireland and VI of Scotland.

On 16 Jun 1739 Robert Ker 2nd Duke Roxburghe (age 30) and Essex Mostyn Duchess Roxburghe were married. He the son of John Ker 1st Duke Roxburghe (age 59) and Mary Finch Duchess Roxburghe (age 62). They were half first cousins.

On 29 Aug 1757 James Wemyss (age 31) and Elizabeth Sutherland were married. She the daughter of William Sutherland 17th Earl Sutherland and Elizabeth Wemyss Countess Sutherland. He the son of James Wemyss 5th Earl Wemyss and Janet Charteris. They were half first cousins.

On 03 Nov 1763 Francis William Drake (age 39) and Elizabeth Heathcote (age 33) were married. They had two daughters. They were half first cousins.

On 01 Oct 1771 Colonel Stephen Digby (age 29) and Lucy Fox-Strangways (age 22) were married. She the daughter of Stephen Fox-Strangways 1st Earl of Ilchester (age 67) and Elizabeth Strangways-Horner Countess Ilchester (age 49). They were half first cousins.

On 07 May 1773 Andrew Foley (age 26) and Elizabeth Tomlinson (age 30) were married. They had two sons and four daughters. They were half first cousins.

On 15 Jul 1774 Prince Charles Louis of Baden (age 19) and Princess Amalie of Hesse-Darmstadt (age 20) were married. They were half first cousins.

On 19 Feb 1777 Louis I Grand Duke of Hesse (age 23) and Princess Louise of Hesse-Darmstadt (age 16) were married. They were half first cousins.

In 1788 Archbishop Charles Manners-Sutton (age 32) and Mary Thoroton were married. They had, probably, eloped. They were half first cousins.

On 09 Dec 1799 Robert King 1st Viscount Lorton (age 26) and Frances Parsons (age 24) were married. He the son of Robert King 2nd Earl Kingston and Caroline Fitzgerald. They were half first cousins.

In 1803 Reverend William Digby (age 28) and Charlotte Elizabeth Digby were married. They were half first cousins.

Before 1805 Jonathan Wathen Phipps aka Waller 1st Baronet (age 35) and Elizabeth Slack (age 30) were married. They had four children. They were half first cousins.

On 09 Dec 1805 Charles Ethelston Nightingale 11th Baronet (age 21) and Maria Dickonson Lady Nightingale (age 16) were married. She by marriage Lady Nightingale of Newport Pond in Essex. They were half first cousins.

Before 30 Dec 1806 Wilbraham Egerton (age 25) and Elizabeth Sykes (age 29) were married. They were half first cousins.

In or before 1807 Richard Ponsonby (age 35) and Frances Staples were married. He the son of William Ponsonby 1st Baron Ponsonby of Imokilly in County Cork and Louisa Molesworth Countess Fitzwilliam (age 57). They were half first cousins.

On 19 Dec 1813 Cornelius "Commodore" Vanderbilt (age 19) and Sophia Johnson were married after which they lived at a boarding house on Broad Street Manhattan. They were half first cousins.

On 02 Aug 1814 Mark Masterman-Sykes 3rd Baronet (age 42) and Mary Elizabeth Egerton Lady Sledmere were married. They were half first cousins.

In 1815 Ernest Augustus King Hanover (age 43) and Frederica Mecklenburg Strelitz Queen Consort Hanover (age 36) were married. She by marriage Duchess Cumberland and Teviotdale. He the son of King George III of Great Britain and Ireland (age 76) and Charlotte Mecklenburg Strelitz Queen Consort England (age 70). They were half first cousins.

In 1823 Robert Smith aka (age 22) and Emma Mary Fitzpatrick Baroness Lyveden were married. She the illegitmate daughter of John Fitzpatrick 2nd Earl Upper Ossory and Elizabeth Wilson. They were half first cousins.

On 08 Apr 1823 William Bryan Cooke 8th Baronet (age 41) and Isabella Cecilia Middleton Lady Cooke were married. They were half first cousins.

Before 09 Aug 1828 Henry Halford 2nd Baronet (age 31) and Barbara Vaughan were married. They were half first cousins.

On 30 Apr 1830 Henry William Petre (age 39) and Adeliza Maria Howard were married. They were half first cousins. He a great x 4 grandson of King Charles II of England Scotland and Ireland.

On 13 May 1830 Ernest Augustus Perceval (age 22) and Beatrice Trevelyan (age 21) were married. They were half first cousins.

On 03 May 1834 Spencer Bulkeley Wynn 3rd Baron Newborough (age 30) and Frances Maria De Winton Baroness Newborough were married at Great Malvern Priory [Map]. She by marriage Baroness Newborough of Newborough in County Wexford. They were half first cousins.

On 06 Oct 1835 Spencer Horatio Walpole (age 29) and Isabella Perceval (age 33) were married. They were half first cousins.

On 25 Jan 1836 Richard Wingfield 6th Viscount Powerscourt (age 21) and Elizabeth Frances Jocelyn Viscountess Powerscout (age 22) were married. She by marriage Viscountess Powerscourt. She the daughter of Robert Jocelyn 3rd Earl Roden (age 47) and Maria Frances Catherine Stapleton Countess Roden. They were half first cousins.

In Apr 1841 Ford Madox Brown (age 19) and Elizabeth Bromley (age 22) were married. They were half first cousins.

On 16 Jan 1861 George Godolphin Osborne 9th Duke Leeds (age 32) and Fanny Georgiana Pitt-Rivers Duchess Leeds (age 24) were married. He the son of George Godolphin Osborne 8th Duke Leeds (age 58) and Harriet Emma Arundel Stewart Duchess Leeds. They were half first cousins.

In 1866 John Walbanke-Childers (age 67) and Selena Radford were married. They were half first cousins.

On 18 Apr 1867 Nathan Meyer 1st Baron Rothschild (age 26) and Emma Louise von Rothschild Baroness Rothschild (age 23) were married. They were half first cousins.

On 05 Aug 1874 William Frederick Waldegrave 9th Earl Waldegrave (age 23) and Mary Dorothea Palmer Countess Waldegrave (age 24) were married. She by marriage Countess Waldegrave. She the daughter of Roundell Palmer 1st Earl Selborne (age 61) and Laura Waldegrave Countess Selborne (age 53). They were half first cousins. He a great x 5 grandson of King James II of England Scotland and Ireland. She a great x 5 granddaughter of King James II of England Scotland and Ireland.

On 23 Jan 1878 Alfonso XII King Spain (age 20) and Maria de las Mercedes Unknown Queen Consort Spain (age 17) were married. She by marriage Queen Consort Spain. She the daughter of Antoine Orléans Duke Montpensier (age 53) and Infanta Luisa Fernanda Duchess of Montpensier (age 45). He the son of Francisco de Asís King Consort Spain (age 55) and Isabella II Queen Spain (age 47). They were half first cousins.

On 03 Feb 1887 Gerald William Henry Codrington 1st Baronet (age 37) and Edith Henrietta Sybil Denison Lady Codrington (age 22) were married. She by marriage Lady Codrington of Dodington. She the daughter of William Henry Forester Denison 1st Earl Londesborough (age 52) and Edith Somerset Countess Londesborough (age 48). They were half first cousins. He a great x 5 grandson of King Charles II of England Scotland and Ireland.

In 1919 Alexander Bannerman Carnegie (age 25) and Susan Ottilia de Rodakowski-Rivers were married. He the son of Charles Noel Carnegie 10th Earl of Southesk (age 64) and Ethel Mary Elizabeth Bannerman Countess Southesk (age 51). They were half first cousins.

On 01 Oct 1930 John Charles Langham 14th Baronet (age 36) and Rosamond Christabel Rashleigh (age 27) were married. They were half first cousins.

Dietrich Cleves VII Count Cleves and Margaret Guelders Countess Cleves were married. She by marriage Countess Cleves. She the daughter of Otto II Duke Guelders and Margaretha Cleves. He the son of Dietrich Cleves VI Count Cleves and Alida d Henry I Sponheim Countess Cleves. They were half first cousins. She a great x 5 granddaughter of King William "Conqueror" I of England.

William Stafford and Isabel Stafford were married. They were half first cousins.

Major William Knollys and Mary Katherine Law were married. He the son of Charles Knollys 4th Earl Banbury and Elizabeth Lister Countess of Banbury. They were half first cousins.

Charles Bourbon Duke Berry Duke Alençon Duke Angoulême and Marie Louise Élisabeth Bourbon Duchess Berry were married. She by marriage Duchess Berry. She the daughter of Philippe Bourbon II Duke Orléans and Françoise Marie Bourbon Duchess Orléans. He the son of Louis "Le Grand Dauphin" Bourbon Duke Burgundy and Maria Anna Victoria Wittelsbach Duchess Burgundy. They were half first cousins. She a great x 3 granddaughter of King James I of England and Ireland and VI of Scotland.