14 Mar is in March.
On 14 Mar 1190 twin boys were born to King Philip II of France (age 24) and Isabelle Flanders Queen Consort France (age 19). The eldest Robert died the same day, the youngest Philip died three days later. Their mother Isabelle Flanders Queen Consort France (age 19) died from childbirth the day after the birth.
On 14 Mar 1271 Stephen Wittelsbach I Duke Bavaria was born to Henry Wittelsbach I Duke Lower Bavaria I Duke Bavaria (age 35) and Elizabeth Duchess Bavaria (age 35). He a great x 3 grandson of King Henry "Curtmantle" II of England.
On 14 Mar 1362 Richard Willoughby (age 72) died. In 1362 Richard Willoughby (age 72) was buried at St Mary & All Saints Church, Willoughby-on-the-Wolds [Map].
On 14 Mar 1369 the army of Henry "Fratricide" II King Castile (age 35) defeated that of his half-brother Peter "Cruel" I King Castile (age 34) at the Battle of Montiel. Henry "Fratricide" II King Castile 1334-1379's army was commanded by Bertrand Geusclin (age 49). Peter "Cruel" I King Castile (age 34) escaped to the castle of Montiel, La Mancha.
On 14 Mar 1406 Thomas Neville Baron Furnivall (age 44) died at Worksop Priory [Map]. His daughter Maud Neville 6th Baroness Furnivall (age 13) succeeded 6th Baroness Furnivall.
After 14 Mar 1420 John Dudley 1st Baron Dudley (age 19) and Elizabeth Berkeley Baroness Cherleton Baroness Dudley were married at Dudley. She a great x 5 granddaughter of King John "Lackland" of England. 
On 14 Mar 1424 Archibald Douglas 1st Duke Touraine (age 52) arrived at La Rochelle with an army of men follwing the request of Charles "Victorious" VII King France (age 21) for aid.
On 14 Mar 1471 King Edward IV of England (age 28) landed at Ravenspur [Map] with William Hastings 1st Baron Hastings (age 40). 
On 14 Mar 1555 John Russell 1st Earl Bedford (age 70) died. His son Francis Russell 2nd Earl Bedford (age 28) succeeded 2nd Earl Bedford 3C 1551, 2nd Baron Russell 1C 1539. Margaret St John Countess Bedford (age 22) by marriage Countess Bedford.
Before 14 Mar 1611 William Alington 1st Baron Alington was born to Giles Alington (age 38). He was baptised on 14 Mar 1611.
On 14 Mar 1629 Robert Barkham (age 75) died. He was buried in Church of St George, South Acre [Map].
Robert Barkham: Around 1554 he was born to Robert Edward Barkham (age 39) and Jane Frances Berney (age 39).
On 14 Mar 1630 Jenico Preston 5th Viscount Gormanston (age 46) died. His son Nicholas Preston 6th Viscount Gormanston (age 22) succeeded 6th Viscount Gormanston.
On 14 Mar 1683 Robert Montagu 3rd Earl Manchester (age 48) died. His son Charles Montagu 1st Duke Manchester (age 21) succeeded 4th Earl Manchester, 4th Viscount Mandeville, 4th Baron Montagu of Kimbolton.
After 14 Mar 1683 Charles Montagu 1st Earl Halifax (age 21) and Anne Yelverton Countess Manchester (age 52) were married. She the widow of his cousin Robert Montagu 3rd Earl Manchester (deceased). The difference in their ages was 30 years.
On 14 Mar 1698 John Fleming 6th Earl Wigtown (age 25) and Margaret Lindsay Countess Wigtown were married. Margaret Lindsay Countess Wigtown by marriage Countess Wigtown. They were divorced in 1708. She the daughter of Colin Lindsay 3rd Earl Balcarres (age 45). He the son of William Fleming 5th Earl Wigtown and Henrietta Seton Countess Wigtown (age 45). They were half second cousin once removed.
After 14 Mar 1711. Gravestone of Eleanor Franklin (deceased) at the Church of St Mary Magdalene, Ecton [Map]. The graves of Eleanor and her husband Thomas were shown to Benjamin Franklin (age 5) when he visited the graveyard in 1758 looking for his grandfather Thomas Franklin which he didn't find.
On 14 Mar 1721 Clotworthy Upton 1st Baron Templetown was born to Lieutenant Colonel John Upton of Castle Upton in County Antrim (age 50) and Mary Upton.
On 14 Mar 1741 John Montagu 4th Earl Sandwich (age 22) and Dorothy Fane Countess Sandwich (age 23) were married. She by marriage Countess Sandwich.
On 14 Mar 1754 Henry Cecil 1st Marquess Exeter was born to Thomas Cecil (age 26).
On 14 Mar 1760 Margaret Fortescue died unmarried. Her second cousin Margaret Rolle Countess Orford (age 51) abeyance terminated 15th Baroness Clinton.
On 14 Mar 1766 James Lumley (age 60) died unmarried, heavily in debt. He left his Durham estates to his nephew Richard Lumley-Saunderson 4th Earl Scarborough (age 40) and his Sussex estates to his nephew George Montagu Dunk 2nd Earl Halifax (age 49).
On 14 Mar 1774 Charles Medows aka Pierrepont 1st Earl Manvers (age 36) and Anne Mills Countess Manvers (age 27) were married at St Mary Magdalene Church, Richmond.
On 14 Mar 1793 Cecil Cardonnel 2nd Baroness Dynevor (age 57) died at Dynevor Castle. Her son George Talbot Rice 3rd Baron Dynevor (age 27) succeeded 3rd Baron Dynevor of Dynevor in Camarthenshire.
On 14 Mar 1794 George Perceval 6th Earl Egmont was born to Charles George Perceval 1st and 2nd Baron Arden (age 37) and Margaretta Elizabeth Wilson Baroness Arden (age 25).
On 14 Mar 1811 Augustus Henry Fitzroy 3rd Duke Grafton (age 75) died. His son George Henry Fitzroy 4th Duke Grafton (age 51) succeeded 4th Duke Grafton 1C 1675, 4th Earl Euston, 4th Viscount Ipswich, 4th Baron Sudbury, 5th Earl Arlington, 5th Viscount Thetford, 5th Baron Arlington of Arlington in Middlesex 1C 1665 and 5th Baron Arlington of Arlington in Middlesex 2C 1672.
On 14 Mar 1812 William Pole Tylney Long Wellesley 4th Earl Mornington (age 23) and Catherine "The Wiltshire Heiress" Tylney Long (age 23) were married. He the son of William Wellesley aka Wellesley-Pole 3rd Earl Mornington (age 48) and Katherine Forbes Countess Mornington (age 51).
On 14 Mar 1826 Thomas Fitzmaurice 5th Earl Orkney (age 22) and Isabella Irby Countess Orkney (age 19) were married.
On 14 Mar 1837 Joan Scott Viscountess Canning (age 60) died. Her son Charles Canning 1st Earl Canning (age 24) succeeded 2nd Viscount Canning.
On 14 Mar 1840 John Parker 1st Earl Morley (age 67) died. His son Edmund Parker 2nd Earl Morley (age 29) succeeded 2nd Earl Morley, 2nd Viscount Boringdon of North Malton in Devon.
On 14 Mar 1855 Claude Bowes-Lyon 14th Earl Strathmore and Kinghorne was born to Claude Bowes-Lyon 13th Earl Strathmore and Kinghorne (age 30) and Frances Dora Smith Countess Strathmore and Kinghorne (age 22) at Lowndes Square.
On 14 Mar 1860 Sidney Carr Hobart-Hampden-Mercer-Henderson 7th Earl Buckinghamshire was born to Frederick John Hobart-Hampden (age 39).
On 14 Mar 1867 Albert Yorke 6th Earl of Hardwicke was born to Charles Philip "Champagne Charlie" Yorke 5th Earl of Hardwicke (age 30) and Sophia Georgiana Robertina Wellesley Countess Hardwicke (age 27).
After 14 Mar 1886. Monument to Lieutenant Mildmay Edward Fane (deceased) at St Nicholas' Church, Fulbeck.
Lieutenant Mildmay Edward Fane: On 29 Dec 1863 he was born to Francis Augustus Fane (age 38) and Augusta Fane (age 32) at Malta. Coefficient of inbreeding 6.25%. From 17 Feb 1885 to 14 Mar 1886 Lieutenant Mildmay Edward Fane (age 22) served at Gibraltar with the 3rd Battalion Rifle Brigade. On 14 Mar 1886 Lieutenant Mildmay Edward Fane (age 22) died.
On 14 Mar 1892 Henry Brand 1st Viscount Hampden (age 77) died. His son Henry Brand 2nd Viscount Hampden (age 50) succeeded 2nd Viscount Hampden 2C 1884, 24th Baron Dacre Gilsland 1C 1321.
On 14 Mar 1901 Arthur Saunders Gore 5th Earl Arran (age 62) died. His son Arthur Gore 6th Earl of Arran (age 32) succeeded 6th Earl Arran 3C 1762.
On 14 Mar 1901 Herbrand Arthur Sackville 11th Duke Bedford (age 43) was appointed 816th Knight of the Garter by King Edward VII of the United Kingdom (age 59).
On 14 Mar 1905 Henry Cyril "Toppy" Paget 5th Marquess Anglesey (age 29) died. He was buried at St Edwen's Church, Llanedwen [Map] in the same grave as his father. His first cousin Charles Henry Alexander Paget 6th Marquess Anglesey (age 19) succeeded 6th Marquess Anglesey, 7th Earl Uxbridge 2C 1784, 9th Baronet Bayly of Plas Newydd in Anglesey.
On 14 Mar 1944 Charles Edward Peter Neil Wood 3rd Earl Halifax was born to Charles Ingram Courtenay Wood 2nd Earl Halifax (age 31) and Ruth Alice Hannah Mary Primrose Countess Halifax (age 27).
On 14 Mar 1946 Dudley McGarel-Hogg 3rd Baron Magheramorne (age 82) died unmarried. He was buried at Brompton Cemetery. His brother Ronald Tracy McGarel-Hogg 4th Baron Magheramorne (age 81) succeeded 4th Baron Magheramorne of Magheramorne in Antrim, 5th Baronet Hogg of Upper Grosvenor Street in London.
