12 Mar is in March.
On 12 Mar 604 Pope Gregory I (age 64) died.
On 12 Mar 951 Bishop Ælfheah "The Bald" died. He was buried at Winchester Old Minster.
On 12 Mar 996 Odo Blois I Count Blois (age 46) died. His son Theobald Blois II Count Blois (age 11) succeeded II Count Blois.
On 12 Mar 1237 William Jülich IV Count Jülich (age 27) and Margaret Guelders Countess Jülich were married. She by marriage Countess Jülich. He would, thirteen years later, marry her sister Richardis Guelders Countess Jülich (age 22); an example of Married to Two Siblings. She the daughter of Gerard III Count Guelders and Margaret Reginar Countess Guelders. He the son of William Jülich III Count Jülich and Matilda Luxemburg Countess Jülich. They were third cousins. She a great x 4 granddaughter of King William "Conqueror" I of England. 
On 12 Mar 1270 Charles Valois I Count Valois was born to Philip "Bold" III King France (age 24) and Isabella Barcelona Queen Consort France (age 22). He a great x 3 grandson of King Henry "Curtmantle" II of England.
On 12 Mar 1281 John Nesle V Count Soissons was born to John Nesle IV Count Soissons and Marguerite Rumigny Countess Soissons.
On 12 Mar 1310 William Leybourne 1st Baron Leybourne (age 68) died at Criccieth Castle [Map].
Around 12 Mar 1312 John de Vere 7th Earl of Oxford was born to Alphonse Vere and Jane Foliot.
On 12 Mar 1336 Guy Dampierre II Count Namur (age 24) was killed in a tournament. His brother Philip Dampierre III Marquis Namur (age 17) succeeded III Marquis Namur.
On 12 Mar 1336 Edward Duke Guelders was born to Reginald "Black" II Duke Guelders (age 41) and Eleanor of Woodstock Plantagenet (age 17). He a grandson of King Edward II of England.
Before 12 Mar 1407 John "Old Talbot" Talbot 1st Earl of Shrewsbury (age 24) and Maud Neville 6th Baroness Furnivall (age 14) were married. He by marriage Baron Furnivall 1C 1295. They were third cousin once removed. He a great x 3 grandson of King Edward "Longshanks" I of England. 
On 12 Mar 1445 John Jacob Marquis of Montferrat (age 49) died. His son John IV Marquis of Montferrat (age 31) succeeded IV Marquis Montferrat.
On 12 Mar 1463 George Douglas 4th Earl Angus (age 36) died. His son Archibald "Bell the Cat" Douglas 5th Earl Angus (age 14) succeeded 5th Earl Angus.
On 12 Mar 1470 King Edward IV of England (age 27) commanded at the Battle of Losecoat Field (Empingham). The battle apparently didn't take place since the army of Robert Welles 8th Baron Willoughby 8th Baron Welles fled in the face of the Royal army. The name 'Losecoat' not contemporary; Battle of Empingham may be. Robert Welles 8th Baron Willoughby 8th Baron Welles was captured with documents describing the fomenting of rebellion by Richard "Kingmaker" Neville Earl Warwick, 6th Earl Salisbury (age 41) and George York 1st Duke of Clarence (age 20).
On 12 Mar 1470 Richard Welles 7th Baron Willoughby 7th Baron Welles (age 42) and Thomas Dymoke (age 42) were beheaded at Queen's Cross Stamford. Note. Some sources say on battlefield immediately prior to the battle.
On 12 Mar 1487 William Gascoigne (age 35) died at Gawthorpe Hall [Map]. All Saints Church Harewood [Map]. Monument to William Gascoigne (age 35) and Margaret Percy (age 40). Fluted Period. Alabaster chest tomb with a fine array of weepers, possibly their children although too many, women one side, nine men the other, one of which appears with angels wings, possible children and spouses. He wearing a Lancastrian Esses Collar with unusual O links. Clean shaved, no bascinet, his head resting on a helm with bulls head crest. His armour plate over which there appears to be, unusually for the period, a tabard. The left hand side of his face appears disfigured. Possibly a war wound. She wearing the widow's barbe. Note. Gardner describes this monument as being to Sir John Nevill of Womersley, died 1482. Chest with Weepers. Chest with Angels with Rounded Wings holding Shields. Angels Supporting Pillow.
William Gascoigne: Around 1452 he was born to William Gascoigne XIII (age 22) and Joan Neville (age 18) at Gawthorpe Hall. Before 1467 William Gascoigne (age 15) and Margaret Percy (age 19) were married. She the daughter of Henry Percy 3rd Earl of Northumberland and Eleanor Poynings Countess Northumberland (age 44). They were half second cousin once removed. He a great x 4 grandson of King Edward III of England. She a great x 3 granddaughter of King Edward III of England. In 1478 William Gascoigne (age 26) was appointed Knight of the Bath. In 1480 William Gascoigne (age 28) received a license to crenellate at Gawthorpe Hall.
Margaret Percy: Around 1447 she was born to Henry Percy 3rd Earl of Northumberland (age 25) and Eleanor Poynings Countess Northumberland (age 25). She a great x 3 granddaughter of King Edward III of England.
On 12 Mar 1500 Cardinal Reginald Pole was born to Richard Pole (age 38) and Margaret York Countess of Salisbury (age 26) at Stourton Castle.
On 12 Mar 1539 Thomas Boleyn 1st Earl Wiltshire and Ormonde (age 62) died. He was buried at St Peter's Church, Hever. His monument has a brass. He is depicted dressed in full robes wearing the insignia of a Knight of the Garter, with the Badge on his left breast and the Garter around his left knee. His head rests on a helm surmounted by a crest of a falcon displayed (his daughter's heraldic badge) and his feet rest on a griffin. The inscription reads: Here lieth Sir Thomas Bullen, Knight of the Order of the Garter, Erle of Wilscher and Erle or Ormunde, which decessed the 12th dai of Marche in the iere of our Lorde 1538. Earl Wiltshire, Earl Ormonde 2C 1529 and Viscount Rochford 1C 1525 extinct. His considerable wealth and properties were inherited were his grand-daughter Queen Elizabeth I of England and Ireland (age 5) and his daughter Mary Boleyn (age 40).
On 12 Mar 1558 George Gordon 5th Earl Huntley and Anne Hamilton Countess Huntley (age 23) were married. She the daughter of James Hamilton 2nd Earl Arran (age 42) and Margaret Douglas Duchess Châtellerault. He the son of George Gordon 4th Earl Huntley (age 44). They were half second cousins.
On 12 Mar 1560. [Some sources say 25 Feb 1560] Catherine Blount (deceased) died. On 11 Aug 1580 Maurice Berkeley (age 74) died. Church of St Mary, Bruton [Map]. Elizabethan Period recumbent effigies of himself and his two wives Catherine Blount (deceased) and Elizabeth Sands (age 27) in an Easter sepulchre-type recess with double round arched front, Corinthian pilasters and strapwork panels. Ruff. Panel with quartered arms 1 
Berkeley Arms 2 probably 
Tiptoft Arms, possibly Wotton Arms 3 Unknown Arms 4 probably 
Babington Arms, possibly 
Zouche Arms differenced with a label three points, overall a Crescent.
Catherine Blount: John Champernowne and she were married. Around 1518 she was born to William Blount 4th Baron Mountjoy (age 40) and Alice Keble Baroness Mountjoy. After 1541 Maurice Berkeley (age 35) and Catherine Blount (age 23) were married. Henry Machyn's Diary. 12 Mar 1560. The xij day of Marche was bered at Dyttun my lade Barkeley (deceased), the wyff of ser Mores Barthelay (age 54) knyght, with a penon of armes and a iiij dosen of skochyons, and a harold of armes, 
Nicholas Narboone Officer of Arms.
Elizabeth Sands: In 1533 she was born to Anthony Sands of Throwley in Kent. In 1562 Maurice Berkeley (age 56) and Elizabeth Sands (age 29) were married. The difference in their ages was 27 years. On 16 Jun 1585 Elizabeth Sands (age 52) died at Berkeley House. She was buried at the St James' Church, Clerkenwell where a monument was constructed. Before 16 Jun 1685 she was appointed Lady of the Bedchamber to Queen Elizabeth I of England and Ireland.
Before 12 Mar 1561 Christopher Plunkett 6th Baron Killeen (age 38) and Ellice Barnewell (age 28) were married. They were second cousins.
Between 12 Mar 1561 and 08 Jun 1561 Christopher Plunkett 6th Baron Killeen (age 38) died. His brother James Plunkett 7th Baron Killeen (age 19) succeeded 7th Baron Killeen.
After 12 Mar 1646 Ralph Hopton 1st Baron Hopton (age 49) with Edward Hyde 1st Earl Clarendon (age 37) and King Charles II of England Scotland and Ireland (age 15) travelled to the Channel Islands [Map].
Before 12 Mar 1663 Richard Lumley 1st Viscount Lumley (age 73) died.
On 12 Mar 1672 Admiral John Holmes (age 32), commanding The Gloucester, and Thomas Butler 6th Earl Ossory (age 37) attacked the Dutch Smyrna Fleet on its return from the Mediterranean beginning the Third Anglo-Dutch War.
Evelyn's Diary. 12 Mar 1672. Now was the first blow given by us to the Dutch convoy of the Smyrna fleet, by Sir Robert Holmes (age 32) and Lord Ossory (age 37), in which we received little save blows, and a worthy reproach for attacking our neighbors ere any war was proclaimed, and then pretending the occasion to be, that some time before, the Merlin yacht chancing to sail through the whole Dutch fleet, their Admiral did not strike to that trifling vessel. Surely, this was a quarrel slenderly grounded, and not becoming Christian neighbors. We are likely to thrive, accordingly. Lord Ossory (age 37) several times deplored to me his being engaged in it; he had more justice and honor than in the least to approve of it, though he had been over-persuaded to the expedition. There is no doubt but we should have surprised this exceeding rich fleet, had not the avarice and ambition of Holmes (age 32) and Spragge (age 52) separated themselves, and willfully divided our fleet, on presumption that either of them was strong enough to deal with the Dutch convoy without joining and mutual help; but they so warmly plied our divided fleets, that while in conflict the merchants sailed away, and got safe into Holland.
On 12 Mar 1678 Archibald Campbell 1st Duke Argyll (age 19) and Elizabeth Tollemache Duchess Argyll (age 18) were married. She the daughter of Lionel Tollemache 3rd Baronet and Elizabeth Murray Duchess Lauderdale (age 51). He the son of Archibald Campbell 9th Earl Argyll (age 49) and Mary Stewart Countess Argyll.
Evelyn's Diary. 12 Mar 1686. A docquet was to be seal' d importing a lease of 21 yeares to one Hall, who styl'd himselfe his Ma*'s (age 52) printer (he lately turn'd Papist) for the printing Missalls, Offices, Lives of Saints, Portals, Primers, &c. books expressly forbidden to be printed or sold, by divers Acts of Parliament; I refus'd to put the seale to it, making my exceptions, so it was laied by.
On 12 Mar 1690 George Henry Lee 2nd Earl Lichfield was born to Edward Lee 1st Earl Lichfield (age 27) and Charlotte Fitzroy Countess Lichfield (age 25). He a grandson of King Charles II of England Scotland and Ireland.
On 12 Mar 1699 John Sheffield 1st Duke of Buckingham and Normanby (age 50) and Catherine Greville Duchess Buckingham and Normandby were married at St Clement Danes Church [Map]. She by marriage Countess Mulgrave. He the son of Edmund Sheffield 2nd Earl Mulgrave and Elizabeth Cranfield Countess Mulgrave (age 91).
On 12 Mar 1703 Aubrey de Vere 20th Earl of Oxford (age 76) died. Earl of Oxford 2C 1141 extinct.
On 12 Mar 1703 Philip Sherard 2nd Earl Harborough (age 23) and Anne Pedley Countess Harborough (age 28) were married.
On 12 Mar 1718 Joseph Damer 1st Earl Dorchester was born to Joseph Damer (age 42).
On 12 Mar 1749 or 13 Mar 1749 William Robert Fitzgerald 2nd Duke Leinster was born to James Fitzgerald 1st Duke Leinster (age 27) and Emilia Mary Lennox Duchess Leinster (age 17) at Arlington Place. He a great x 2 grandson of King Charles II of England Scotland and Ireland.
On 12 Mar 1751 Charles Wyndham 2nd Earl Egremont (age 40) and Alicia Carpenter Countess Egremont (age 25) were married. She by marriage Countess Egremont.
On 12 Mar 1751 Henry Lowther 3rd Viscount Lonsdale (age 57) died unmarried. Viscount Lonsdale in Westmoreland extinct.
On 12 Mar 1753 Hugh Fortescue 1st Earl Fortescue was born to Matthew Fortescue 2nd Baron Fortescue (age 34) and Anne Campbell Baroness Fortescue (age 25).
On 12 Mar 1764 Charles Townshend 3rd Viscount Townsend (age 63) died. His son George Townshend 1st Marquess Townshend (age 40) succeeded 4th George Townshend 1st Marquess Townshend (age 40), 4th Baron Townshend of Lynn Regis in Norfolk, 6th Baronet Townshend. His son George Townshend 1st Marquess Townshend (age 40) succeeded 4th Viscount Townsend.
On 12 Mar 1772 William Hay 17th Earl Erroll was born to James Hay 15th Earl Erroll (age 45) and Isabella Carr Countess Erroll.
Archaeologia Volume 3 Section XXX. Extract of a Letter from the Reverend Mr. George Low, to Mr. Paton, of Edinburgh. Communicated by Mr. Gough. Read at the Society of Antiquaries, March 12, 19, 1773.
On 12 Mar 1798 Charles Abbot 2nd Baron Colchester was born to Charles Abbot 1st Baron Colchester (age 40).
On 12 Mar 1833 Francis Mathew 2nd Earl Landaff (age 65) died without issue. Earl Llandaff of Thomastown in Tipperary extinct.
On 12 Mar 1856 George Irby 3rd Baron Boston (age 78) died. His son George Ives Irby 4th Baron Boston (age 53) succeeded 4th Baron Boston, 5th Baronet Irby of Whaplode and Boston. Fanny Elizabeth Hopkins-Northey Baroness Boston (age 47) by marriage Baroness Boston.
After 12 Mar 1868. Monument to General Mildmay Fane (deceased) at St Nicholas' Church, Fulbeck. Inscription ... In memory of General Mildmay Fane 7th son of the Honble H. Fane of Fulbeck who served in the Peninsula at the Battle of Vittoria, Assault & Capture of San Sebastian and the Battle of the Nile, also in the Campaign of 1815 including the Battle of Quatre Bras in which he was wounded. Died March 12th 1868, aged 73. This tablet was erected by officers of the 54th Regiment who served under him as their commanding officer between 1828 and 1851 in token of their great esteem for his memory and of honour , respect and love with which they regarded him.
General Mildmay Fane: In Sep 1794 he was born to Henry Fane of Fulbeck (age 55) and Anne Buckley Batson (age 36). In 1810 General Mildmay Fane (age 15) joined the Army. On 27 Mar 1863 General Mildmay Fane (age 68) was promoted to General. On 12 Mar 1868 General Mildmay Fane (age 73) died from a fall from his horse whilst hunting. He was unmarried.
On 12 Mar 1884 Lucius Cary 10th Viscount Falkland (age 80) died. His brother Admiral Plantagenet Cary 11th Viscount Falkland (age 77) succeeded 11th Viscount Falkland.
On 12 Mar 1898 Orlando Bridgeman 3rd Earl Bradford (age 78) died at Weston Park, Staffordshire. His son George Cecil Orlando Bridgeman 4th Earl Bradford (age 53) succeeded 4th Earl Bradford 2C 1815, 5th Baron Bradford in Shropshire, 9th Baronet Bridgeman of Great Lever in Lancashire. Ida Frances Annabella Lumley Countess Bradford (age 49) by marriage Countess Bradford.
On 12 Mar 1901 John Francis Godolphin Osborne 11th Duke Leeds was born to George Godolphin Osborne 10th Duke Leeds (age 38) and Katherine Frances Lambton Duchess Leeds (age 38).
On 12 Mar 1901 William Horsley-Beresford 4th Baron Decies (age 36) and Maria Gertrude Willoughby were married.
On 12 Mar 1997 William Hare 5th Earl of Listowel (age 90) died. His son Francis Hare 6th Earl of Listowel (age 32) succeeded 6th Earl Listowel in County Kerry.
On 12 Mar 2004 Francis Henry Coventry 12th Earl Coventry (age 91) died. His fourth cousin George William Coventry 13th Earl Coventry (age 64) succeeded 13th Earl Coventry.
