In 1885 [his father] William George Frederick Cavendish-Bentinck (age 29) and [his mother] Ruth Mary St Maur (age 17) were married.
On 04 Jul 1889 Ferdinand Cavendish-Bentinck 8th Duke of Portland was born to William George Frederick Cavendish-Bentinck (age 33) and Ruth Mary St Maur (age 21).
In 1948 [his father] William George Frederick Cavendish-Bentinck (age 92) died.
On 28 Jan 1953 [his mother] Ruth Mary St Maur (age 85) died.
On 21 Mar 1977 William Arthur Henry Cavendish-Bentinck 7th Duke Portland 1893-1977 (age 84) died. His third cousin Ferdinand Cavendish-Bentinck 8th Duke of Portland (age 87) succeeded 8th Duke Portland, 9th Earl of Portland. Baron Bolsover of Bolsover in Derbyshire extinct.
On 13 Dec 1980 Ferdinand Cavendish-Bentinck 8th Duke of Portland (age 91) died. His brother [his brother] Victor Cavendish-Bentinck 9th Duke of Portland 1897-1990 (age 83) succeeded 9th Duke Portland, 10th Earl of Portland.
Paternal Family Tree: Bentinck
Kings Wessex: Great x 25 Grand Son of King Edmund "Ironside" I of England
Kings Gwynedd: Great x 21 Grand Son of Owain "Great" King Gwynedd 1100-1170
Kings Seisyllwg: Great x 27 Grand Son of Hywel "Dda aka Good" King Seisyllwg King Deheubarth
Kings Powys: Great x 22 Grand Son of Maredudd ap Bleddyn King Powys 1047-1132
Kings England: Great x 12 Grand Son of King Henry VII of England and Ireland
Kings Scotland: Great x 18 Grand Son of Robert "The Bruce" I King Scotland
Kings Franks: Great x 21 Grand Son of Louis VII King Franks
Kings France: Great x 15 Grand Son of Charles "Beloved Mad" VI King France
Great x 4 Grandfather: Henry Bentinck 1st Duke Portland 1682-1726 11 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: William Bentinck 2nd Duke Portland 1709-1762 11 x Great Grand Son of Henry IV King England
Great x 4 Grandmother: Elizabeth Noel Duchess Portland 1688-1737
10 x Great Grand Daughter of Henry IV King England
Great x 2 Grandfather: William Cavendish-Bentinck 3rd Duke Portland 9 x Great Grand Son of King Edward IV of England
Great x 4 Grandfather: Edward Harley 2nd Earl of Oxford and Earl Mortimer 11 x Great Grand Son of King Edward III of England
Great x 3 Grandmother: Margaret Cavendish Harley 2nd Duchess Portland 1715-1785 8 x Great Grand Daughter of King Edward IV of England
Great x 4 Grandmother: Henrietta Cavendish Holles Countess of Oxford and Mortimer 1694-1755 7 x Great Grand Daughter of King Edward IV of England
Great x 1 Grandfather: Frederick Cavendish-Bentinck 9 x Great Grand Son of King Henry VII of England and Ireland
Great x 4 Grandfather: William Cavendish 3rd Duke Devonshire
10 x Great Grand Son of Henry IV King England
Great x 3 Grandfather: William Cavendish 4th Duke Devonshire 11 x Great Grand Son of Henry IV King England
Great x 2 Grandmother: Dorothy Cavendish 3rd Duchess Portland 1750-1794 8 x Great Grand Daughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Richard Boyle 3rd Earl Burlington
6 x Great Grand Son of King Henry VII of England and Ireland
Great x 3 Grandmother: Charlotte Elizabeth Boyle Marchioness Hartington 7 x Great Grand Daughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Dorothy Savile Countess Burlington
11 x Great Grand Daughter of King Edward III of England
GrandFather: George Cavendish-Bentinck 10 x Great Grand Son of King Henry VII of England and Ireland
Great x 4 Grandfather: Christopher Lowther
Great x 3 Grandfather: William Lowther 1st Baronet
Great x 2 Grandfather: William Lowther 1st Earl Lonsdale
Great x 1 Grandmother: Mary Lowther 13 x Great Grand Daughter of King Edward III of England
Great x 4 Grandfather: Thomas Fane 8th Earl of Westmoreland 1701-1771
10 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: John Fane 9th Earl of Westmoreland 11 x Great Grand Son of King Edward III of England
Great x 2 Grandmother: Augusta Fane Countess Lonsdale 1761-1838 12 x Great Grand Daughter of King Edward III of England
Great x 4 Grandfather: Montagu Bertie
11 x Great Grand Son of King Edward III of England
Great x 3 Grandmother: Augusta Bertie 12 x Great Grand Daughter of King Edward III of England
Great x 4 Grandmother: Elizabeth Piers
Father: William George Frederick Cavendish-Bentinck 11 x Great Grand Son of King Henry VII of England and Ireland
Great x 1 Grandfather: Charles Powell Leslie
GrandMother: Prudence Penelope Cavendish-Bentinck nee Leslie
Ferdinand Cavendish-Bentinck 8th Duke of Portland 1889-1980 12 x Great Grand Son of King Henry VII of England and Ireland
Great x 4 Grandfather: Edward Seymour 8th Duke Somerset 1695-1757 11 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: Webb Seymour 10th Duke Somerset 1718-1793 12 x Great Grand Son of King Edward III of England
Great x 2 Grandfather: Edward Seymour 11th Duke Somerset 13 x Great Grand Son of King Edward III of England
Great x 1 Grandfather: Edward Adolphus Seymour 12th Duke Somerset 13 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: James Hamilton 5th Duke Hamilton 2nd Duke Brandon
10 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: Archibald Hamilton 9th Duke Hamilton 6th Duke Brandon 11 x Great Grand Son of King Edward III of England
Great x 4 Grandmother: Anne Spencer Duchess Hamilton Duchess Brandon 1710-1771
Great x 2 Grandmother: Charlotte Hamilton Duchess Somerset 1772-1827 12 x Great Grand Daughter of King Edward III of England
Great x 4 Grandfather: Alexander Stewart 6th Earl Galloway
11 x Great Grand Son of King Edward III of England
Great x 3 Grandmother: Harriet Stewart Duchess Hamilton Duchess Brandon -1788 12 x Great Grand Daughter of King Edward III of England
GrandFather: Edward Adolphus Ferdinand Seymour 14 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: Richard Brinsley Sheridan
Great x 2 Grandfather: Thomas Sheridan
Great x 4 Grandfather: Thomas Linley
Great x 3 Grandmother: Elizabeth Anne Linley
Great x 1 Grandmother: 21 x Great Grand Daughter of King John "Lackland" of England
Great x 3 Grandfather: Colonel James Campbell of Ardkinglass
Great x 2 Grandmother: Caroline Henrietta Callander 20 x Great Grand Daughter of King John "Lackland" of England
Mother: Ruth Mary St Maur 15 x Great Grand Daughter of King Edward III of England
GrandMother: Rosina Elizabeth Swan Maid