Paternal Family Tree: Cavendish
Maternal Family Tree: Anna Maria Mordaunt -1771
On 3rd August 1865 [his father] Edward Cavendish [aged 27] and [his mother] Emma Elizabeth Lascelles were married. He the son of [his grandfather] William Cavendish 7th Duke Devonshire [aged 57] and [his grandmother] Blanche Georgiana Howard. They were first cousins.
On 25th March 1875 John Spencer Cavendish was born to Edward Cavendish [aged 37] and Emma Elizabeth Lascelles. He was baptised on 15th May 1875 in the parish of Christ Church, Mayfair. He was educated at Eton and Trinity College, Cambridge. Coefficient of inbreeding 6.69%.
On 18th May 1891 [his father] Edward Cavendish [aged 53] died. Monument to Edward Cavendish in Cartmel Priory, Lancashire [Map].
Edward Cavendish: On 28th January 1838 he was born to William Cavendish 7th Duke Devonshire and Blanche Georgiana Howard at Marylebone. Coefficient of inbreeding 1.65%. On 3rd August 1865 Edward Cavendish and Emma Elizabeth Lascelles were married. He the son of William Cavendish 7th Duke Devonshire and Blanche Georgiana Howard. They were first cousins.
On 30th July 1892 [his brother] Victor Christian William Cavendish 9th Duke Devonshire [aged 24] and [his sister-in-law] Evelyn Emily Mary Petty-Fitzmaurice Duchess Devonshire [aged 21] were married. She by marriage Duchess Devonshire. She the daughter of Henry Petty-Fitzmaurice 5th Marquess Lansdowne [aged 47]. They were fifth cousins.
The London Gazette 26498. John Spencer Cavendish [aged 18], Gent., to be Second Lieutenant. Dated 10th March 1894.
On 5th March 1895 John Spencer Cavendish [aged 19] was initiated to Isaac Newton University No 859 EC.
The London Gazette 26819. 2nd February 1897. 1st Life Guards, Lieutenant John Spencer Cavendish [aged 21], from 3rd Battalion the Royal Scots (Lothian Regiment), to be Second Lieutenant, in succession to Lieutenant B. D'A. Corbet, resigned. Dated 3rd February, 1897.
On 3rd February 1897 John Spencer Cavendish [aged 21] was given a commission in the 1st Life Guards. He was promoted to Lieutenant on 2nd April 1898, Captain on 23rd August 1902, and Major on 12th April 1911.
Between 1899 and 1902 John Spencer Cavendish [aged 23] served with distinction on the Staff in the South African War 1899-1902, being divisional Signalling Officer to the 2nd Infantry Division from 9th October 1899 to 18th June 1900, and Brigade Signalling Officer, 19th June to 12 October 1900.
On 15th December 1899 the Battle of Colenso was fought between British and Boer forces from the independent South African Republic and Orange Free State in and around Colenso, Natal, South Africa; the British were defeated.
John Spencer Cavendish [aged 24] took part.
Between 20th January 1900 and 24th January 1900 General Buller [aged 60] with 30,000 men under his command attempted to capture Scion Kop hill as a step towards relieving Ladysmith. On the night of 23 January in heavy mist the British launched an attack on what they thought was Spion Kop, but it turned out to be a smaller mound some 500 m from the main peak. The following day there was bloody fighting as the British tried to force their way to the top of the main peak. By nightfall both sides thought that the other had taken the hill, so they abandoned their positions and it was only once a Boer scout realised the situation that the Boers retook the hill and the British withdrew back across the Tugela.
John Spencer Cavendish [aged 24] was present.
From 5th February 1900 to 7th February 1900. The Battle of Vaal Krantz was fought at Vaal Krantz, Natal between General Redvers Buller's British army and Louis Botha's army of Boer irregulars and lift the Siege of Ladysmith. Buller tried, unsuccessfully, to force a bridgehead across the Tugela River.
John Spencer Cavendish [aged 24] was present.
Lieutenant Charles Duncombe Shafto [aged 22] was killed in action whilst serving with the Durham Light Infantry.
Between 14th February 1900 and 27th February 1900 the Battle of Tugela Heights aks Pieters Hill was a series of military actions in which General Buller's [aged 60] British army forced Louis Botha's Boer army to lift the Siege of Ladysmith.
John Spencer Cavendish [aged 24] was present.
Between 29th June 1907 and 6th Septemberr 1910 John Spencer Cavendish [aged 32] was employed with the West African Frontier Force.
On 24th March 1908 [his uncle] Spencer Cavendish 8th Duke Devonshire [aged 74] died of pneumonia at Hotel Metropol. His nephew [his brother] Victor [aged 39] succeeded 9th Duke Devonshire, 12th Earl Devonshire, 4th Earl Burlington, 12th Baron Cavendish Hardwick. On 28th March 1908 he was buried in the Cavendish Plot, St Peter's Church, Edensor [Map].
The Deeds of the Dukes of Normandy
The Gesta Normannorum Ducum [The Deeds of the Dukes of Normandy] is a landmark medieval chronicle tracing the rise and fall of the Norman dynasty from its early roots through the pivotal events surrounding the Norman Conquest of England. Originally penned in Latin by the monk William of Jumièges shortly before 1060 and later expanded at the behest of William the Conqueror, the work chronicles the deeds, politics, battles, and leadership of the Norman dukes, especially William’s own claim to the English throne. The narrative combines earlier historical sources with firsthand information and oral testimony to present an authoritative account of Normandy’s transformation from a Viking settlement into one of medieval Europe’s most powerful realms. William’s history emphasizes the legitimacy, military prowess, and governance of the Norman line, framing their expansion, including the conquest of England, as both divinely sanctioned and noble in purpose. Later chroniclers such as Orderic Vitalis and Robert of Torigni continued the history, extending the coverage into the 12th century, providing broader context on ducal rule and its impact. Today this classic work remains a foundational source for understanding Norman identity, medieval statesmanship, and the historical forces that reshaped England and Western Europe between 800AD and 1100AD.
Available at Amazon in eBook and Paperback format.
The London Gazette 28193. Whitehall, October 30, 1908. The KING, taking into His Royal consideration that upon the decease of [his uncle] Spencer Compton Cavendish, Duke of Devonshire, without male issue, on the twenty-fourth day of March last, the title and dignity of Duke of Devonshire devolved upon Victor Christian William Caven dish, now Duke of Devonshire, as the eldest son and heir of Edward Cavendish, commonly called Lord Edward Cavendish, whereby according to the ordinary rules of honour the brothers of the said Victor Christian William Cavendish, Duke of Devonshire, cannot enjoy the title, rank, place and precedence which would have been due to them had their father survived the said Spencer Cornpton Cavendish, Duke of Devonshire, and succeeded to the title and dignity of Duku of Devonshire, His Majesty hus been graciously pleased to ordain and declare that Richard Frederick Cavendish [aged 37], of Holker Hall, Cark in Cartmel, in the county of Lancaster, Esquire, and John Spencer Cavendish [aged 33], Esquire, Companion of the Distinguished Order, Captain, 1st Life Guards, now residing at Carlos-place, Grosvenor square, in the county of London, shall have, hold and enjoy the same title, rank, place, pre-eminence and precedence as if their late father, the said Lord Edward Cavendish had survived the said Spencer Compton Cavendish, Duke of Devonshire, and thereby succeeded to the title and dignity of Duke of Devonshire.
And to command that the said Royal order and declaration be registered in His Majesty's College of Arms
On 24th February 1909 John Spencer Cavendish [aged 33] joined Household Brigade No 2614 EC.
On 7th August 1909 John Spencer Cavendish [aged 34] joined Northern Nigeria No 3325 EC.
On 16th August 1914 John Spencer Cavendish [aged 39] disembarked in France.
On 20th October 1914 John Spencer Cavendish [aged 39] was killed in action. A note on the website of the Household Brigade Lodge No. 2614 suggests the following: "An account of John's death by an unknown soldier, dated 24 October 1914, who served alongside him recalls that 'Lord John' was killed instantly by German Maxim Machine Gun fire whilst leading a regiment trying to hold the line in the village." He was buried in the Caberet Rouge Cemetery at Souchez and that he was first interred in the German extension of the cemetery of Quesnoy-sur-Deule.
After 20th October 1914 John Spencer Cavendish [deceased] was awarded the 1914 Star, Victory Medal and the British War Medal. His medals were sent to [his mother] Lady Edward Cavendish.
1st March 1915. Probate John Spencer Cavendish. "CAVENDISH the right honourable Lord Cavendish John Spencer of 6 Carlos Place Middlesex D.S.O. died 20 October 1914 in France on active service Probate London 1 March to the most noble Victor Christian William Duke of Devonshire. Effects £45432 4s 3d." The executor of John's estate was listed as [his brother] His Grace, the Duke of Devonshire [aged 46].
After 1919. St Peter's Church, Edensor [Map]. War Memorial including John Spencer Cavendish.
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
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
Kings Godwinson: Great x 25 Grand Son of King Harold II of England
Kings England: Great x 12 Grand Son of King Henry VII of England and Ireland
Kings Scotland: Great x 17 Grand Son of King Robert III of Scotland
Kings France: Great x 15 Grand Son of Charles "Beloved Mad" VI King France
Kings Duke Aquitaine: Great x 29 Grand Son of Ranulf I Duke Aquitaine
Kings Spain: Great x 21 Grand Son of Alfonso VII King Castile VII King Leon
Great x 4 Grandfather: William Cavendish 3rd Duke Devonshire 
10 x Great Grandson of King Henry IV of England
Great x 3 Grandfather: William Cavendish 4th Duke Devonshire 11 x Great Grandson of King Henry IV of England
Great x 4 Grandmother: Catherine Hoskins Duchess Devonshire
Great x 2 Grandfather: George Augustus Henry Cavendish 1st Earl Burlington 8 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Richard Boyle 3rd Earl Burlington 
6 x Great Grandson of King Henry VII of England and Ireland
Great x 3 Grandmother: Charlotte Elizabeth Boyle Marchioness Hartington 7 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Dorothy Savile Countess Burlington 
11 x Great Granddaughter of King Edward III of England
Great x 1 Grandfather: William Cavendish 9 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Charles Compton 
10 x Great Grandson of King Edward III of England
Great x 3 Grandfather: Charles Compton 7th Earl of Northampton 11 x Great Grandson of King Edward III of England
Great x 4 Grandmother: Mary Lucy 
10 x Great Granddaughter of King Edward III of England
Great x 2 Grandmother: Elizabeth Compton Countess Burlington 12 x Great Granddaughter of King Edward III of England
Great x 4 Grandfather: Charles Noel Somerset 4th Duke Beaufort 
11 x Great Grandson of King Henry IV of England
Great x 3 Grandmother: Anne Somerset Countess Northampton 12 x Great Granddaughter of King Henry IV of England
Great x 4 Grandmother: Elizabeth Berkeley Duchess Beaufort 
13 x Great Granddaughter of King Edward I of England
Grandfather: William Cavendish 7th Duke Devonshire 10 x Great Grandson of King Henry VII of England and Ireland
Great x 1 Grandmother: Louisa O'Callaghan
father: Edward Cavendish 11 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Charles Howard 3rd Earl Carlisle 
9 x Great Grandson of King Edward III of England
Great x 3 Grandfather: Henry Howard 4th Earl Carlisle 10 x Great Grandson of King Edward III of England
Great x 4 Grandmother: Anne Capell Countess Carlisle 9 x Great Granddaughter of King Edward III of England
Great x 2 Grandfather: Frederick Howard 5th Earl Carlisle 11 x Great Grandson of King Edward III of England
Great x 4 Grandfather: William Byron 4th Baron Byron 
14 x Great Grandson of King John of England
Great x 3 Grandmother: Isabella Byron Countess Carlisle 12 x Great Granddaughter of King Edward I of England
Great x 4 Grandmother: Frances Berkeley Baroness Byron 11 x Great Granddaughter of King Edward I of England
Great x 1 Grandfather: George Howard 6th Earl Carlisle 9 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: John Leveson-Gower 1st Earl Gower 10 x Great Grandson of King Edward III of England
Great x 3 Grandfather: Granville Leveson-Gower 1st Marquess Stafford 10 x Great Grandson of King Edward III of England
Great x 4 Grandmother: Evelyn Pierrepont Baroness Gower 
9 x Great Granddaughter of King Edward III of England
Great x 2 Grandmother: Margaret Caroline Leveson-Gower Countess Carlisle 8 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Scroop Egerton 1st Duke Bridgewater 
6 x Great Grandson of King Henry VII of England and Ireland
Great x 3 Grandmother: Louisa Egerton Countess Gower 7 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Rachel Russell Duchess Bridgewater 
10 x Great Granddaughter of King Henry IV of England
Grandmother: Blanche Georgiana Howard 10 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: William Cavendish 3rd Duke Devonshire 10 x Great Grandson of King Henry IV of England
Great x 3 Grandfather: William Cavendish 4th Duke Devonshire 11 x Great Grandson of King Henry IV of England
Great x 4 Grandmother: Catherine Hoskins Duchess Devonshire
Great x 2 Grandfather: William Cavendish 5th Duke Devonshire 8 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Richard Boyle 3rd Earl Burlington 6 x Great Grandson of King Henry VII of England and Ireland
Great x 3 Grandmother: Charlotte Elizabeth Boyle Marchioness Hartington 7 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Dorothy Savile Countess Burlington 11 x Great Granddaughter of King Edward III of England
Great x 1 Grandmother: Georgiana Cavendish Countess Carlisle 9 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: John Spencer 
11 x Great Grandson of King Edward III of England
Great x 3 Grandfather: John Spencer 1st Earl Spencer 9 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandmother: Georgiana Caroline Carteret 
8 x Great Granddaughter of King Henry VII of England and Ireland
Great x 2 Grandmother: Georgiana Spencer Duchess Devonshire 10 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Stephen Poyntz 
13 x Great Grandson of King Henry III of England
Great x 3 Grandmother: Margaret Georgiana Poyntz Countess Spencer 11 x Great Granddaughter of King Edward III of England
Great x 4 Grandmother: Anna Maria Mordaunt 
10 x Great Granddaughter of King Edward III of England
John Spencer Cavendish 12 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Daniel Lascelles 
Great x 3 Grandfather: Edward Lascelles
Great x 4 Grandmother: Mary Lascelles
Great x 2 Grandfather: Edward Lascelles 1st Earl Harewood
Great x 1 Grandfather: Henry Lascelles 2nd Earl Harewood
Great x 4 Grandfather: Edward Chaloner
Great x 3 Grandfather: William Chaloner
Great x 4 Grandmother: Anne Bowes
Great x 2 Grandmother: Anne Chaloner Baroness Harewood
Grandfather: William Lascelles
Great x 1 Grandmother: Henrietta Sebright Countess Harewood
mother: Emma Elizabeth Lascelles 11 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Charles Howard 3rd Earl Carlisle 9 x Great Grandson of King Edward III of England
Great x 3 Grandfather: Henry Howard 4th Earl Carlisle 10 x Great Grandson of King Edward III of England
Great x 4 Grandmother: Anne Capell Countess Carlisle 9 x Great Granddaughter of King Edward III of England
Great x 2 Grandfather: Frederick Howard 5th Earl Carlisle 11 x Great Grandson of King Edward III of England
Great x 4 Grandfather: William Byron 4th Baron Byron 14 x Great Grandson of King John of England
Great x 3 Grandmother: Isabella Byron Countess Carlisle 12 x Great Granddaughter of King Edward I of England
Great x 4 Grandmother: Frances Berkeley Baroness Byron 11 x Great Granddaughter of King Edward I of England
Great x 1 Grandfather: George Howard 6th Earl Carlisle 9 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: John Leveson-Gower 1st Earl Gower 10 x Great Grandson of King Edward III of England
Great x 3 Grandfather: Granville Leveson-Gower 1st Marquess Stafford 10 x Great Grandson of King Edward III of England
Great x 4 Grandmother: Evelyn Pierrepont Baroness Gower 9 x Great Granddaughter of King Edward III of England
Great x 2 Grandmother: Margaret Caroline Leveson-Gower Countess Carlisle 8 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Scroop Egerton 1st Duke Bridgewater 6 x Great Grandson of King Henry VII of England and Ireland
Great x 3 Grandmother: Louisa Egerton Countess Gower 7 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Rachel Russell Duchess Bridgewater 10 x Great Granddaughter of King Henry IV of England
Grandmother: Caroline Georgiana Howard 10 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: William Cavendish 3rd Duke Devonshire 10 x Great Grandson of King Henry IV of England
Great x 3 Grandfather: William Cavendish 4th Duke Devonshire 11 x Great Grandson of King Henry IV of England
Great x 4 Grandmother: Catherine Hoskins Duchess Devonshire
Great x 2 Grandfather: William Cavendish 5th Duke Devonshire 8 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandfather: Richard Boyle 3rd Earl Burlington 6 x Great Grandson of King Henry VII of England and Ireland
Great x 3 Grandmother: Charlotte Elizabeth Boyle Marchioness Hartington 7 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandmother: Dorothy Savile Countess Burlington 11 x Great Granddaughter of King Edward III of England
Great x 1 Grandmother: Georgiana Cavendish Countess Carlisle 9 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: John Spencer 11 x Great Grandson of King Edward III of England
Great x 3 Grandfather: John Spencer 1st Earl Spencer 9 x Great Grandson of King Henry VII of England and Ireland
Great x 4 Grandmother: Georgiana Caroline Carteret 8 x Great Granddaughter of King Henry VII of England and Ireland
Great x 2 Grandmother: Georgiana Spencer Duchess Devonshire 10 x Great Granddaughter of King Henry VII of England and Ireland
Great x 4 Grandfather: Stephen Poyntz 13 x Great Grandson of King Henry III of England
Great x 3 Grandmother: Margaret Georgiana Poyntz Countess Spencer 11 x Great Granddaughter of King Edward III of England
Great x 4 Grandmother: Anna Maria Mordaunt 10 x Great Granddaughter of King Edward III of England