23 Sep is in September.
Anglo-Saxon Chronicle. 788. This year Elwald, king of the Northumbrians, was slain by Siga, on the eleventh day before the calends of October; and a heavenly light was often seen on the spot where he was slain. He was buried in the church of Hexham [Map]; and Osred, the son of Alred, who was his nephew, succeeded him in the government. This year there was a synod assembled at Acley.
On 23 Sep 788 Ælfwald I King of Northumbria was murdered. He was buried at Hexham Abbey [Map]. His nephew Osred King of Northumbria succeeded King Northumbria.
On 23 Sep 1338 a French fleet attacked an English fleet unloading cargo at Walcheren. Five large and powerful English cogs, including Edward III's (age 25) flagships the Cog Edward and the Christopher were captured. The captured crews were executed and the ships added to the French fleet.
On 23 Sep 1390 John Metz I Duke Lorraine (age 44) died. His son Charles Metz II Duke Lorraine (age 26) succeeded II Duke Lorraine.
On 23 Sep 1448 Adolph La Marck I Duke Cleves (age 75) died.
On 23 Sep 1450 William Tresham was killed by a group of men as a result of a propery dispute before he was tried for treason.
On 23 Sep 1454 Charles Artois Count Eu (age 60) and Helen Melun Countess Eu (age 84) were married. She by marriage Countess Eu. The difference in their ages was 24 years. He the son of Philip Artois Count Eu and Marie Valois I Duchess Auverge. He a great x 4 grandson of King Henry III of England. 
On 23 Sep 1459 John Dudley 1st Baron Dudley (age 58) attempted to ambush John Neville 1st Marquess Montagu (age 28) whilst he was travelling to Ludlow [Map] to join up with the main Yorkist army; the Battle of Blore Heath. Forewarned by scouts he arranged his troops into battle order. The Yorkist army included John Conyers Sheriff of Yorkshire (age 48), Thomas Harrington (age 59), James Harrington (age 29), Richard Neville 5th Earl Salisbury (age 59), William Stanley (age 24), Roger Kynaston of Myddle and Hordley (age 26), John Savile, Walter Strickland (age 48) and John Wenlock 1st Baron Wenlock (age 59).
The Lancastrian army included brothers John Dutton, Thomas Dutton (age 38) and Peter Dutton who were killed.
James Tuchet 5th Baron Audley, 2nd Baron Tuchet (age 61) was killed by Roger Kynaston of Myddle and Hordley (age 26). His son John Tuchet 6th Baron Audley, 3rd Baron Tuchet (age 33) succeeded 6th Baron Audley of Heighley in Staffordshire, 3rd Baron Tuchet. Anne Echingham Baroness Audley Heighley (age 39) by marriage Baroness Audley of Heighley in Staffordshire, Baroness Audley of Heighley in Staffordshire.
John Dudley 1st Baron Dudley (age 58) and Edmund Dudley (age 34) were captured. Lionel Welles 6th Baron Welles (age 53) fought.
Richard Molyneux of Sefton was killed.
John Egerton (age 55) was killed.
Adam Bostock (age 46) was killed.
After the battle Margaret of Anjou Queen Consort England (age 29) took refuge at Eccleshall Castle [Map].
After the battle Thomas Harrington (age 59), John Neville 1st Marquess Montagu (age 28) and Thomas Neville (age 29) were captured at Acton Bridge Tarporley [Map] and imprisoned at Chester Castle [Map] having been detached from the main Yorkist force.
William Troutbeck (age 23) was killed.
Chronicle of Gregory 1459. 23 Sep 1459. Ande thys yere was done a grete jornaye at the Blowre Hethe by the Erle of Saulysbury (age 59) ande the Quenys galentys. And that day the kynge made vij knyghtys, fyrste, Syr Robert Molyners, Syr John Daune, Syr Thomas Uttyng, Syr John Brembly, Syr Jon Stanley, Syr John Grysly, and Syr Rychard Hardon; and v of thes knyghtys were slayne fulle manly in the fylde, and many men of yemonry soore hurte, and a fulle nobylle knyght, the Lorde Audeley (age 61), and Syr Thomas Hamdon, knyght, was the getynge of the fylde, and Thomas Squyer and Counteroller of the Pryncys house fulle sore hurte. And [the] batayle or jornay lastyd alle the aftyr none, fro one of the clocke tylle v aftyr non, and the chasse lastyd unto vij at the belle in the mornynge. And men were maymyd many one in the Quenys party. There were in the Quenys party vM [Note. 5000], and in that othyr party vC [Note. 500], a grete wondyr that evyr they myght stonde the grete multytude not ferynge, the kynge beyng with yn x myle and the quene (age 29) with yn v myle at the castelle of Egyllyssale [Map]. But the Erle of Saulysbury (age 59) hadde ben i-take, save only a Fryer Austyn schot gonnys [Note. shot guns] alle that nyght in a parke that was at the backe syde of the fylde, and by thys mene the erle come to Duke of Yorke (age 48). And in the morowe they founde nothyr man ne ehylde in that parke but the fryer, and he sayde that for fere he a-bode in that parke alle that nyght. But in the mornyng, by-twyne the fylde and Chester, Syr John Dawne ys sone that was at home in hys fadyrs place hadde worde that hys fadyr was slayne; a-non he raysyd hys tenantys and toke by-syde a lytyl towne i-namyd Torperlay [Map] Syr Thomas Nevyle (age 29), Syr John Nevyle (age 28), and Syr Thomas Haryngdon (age 59), and brought hem unto the castelle of Chester, ande there they a-boode tylle the batayle of Northehampton was done, &c.
On 23 Sep 1461 Charles "Viana" IV King Navarre (age 40) died. His sister Blanche Trastámara II Queen Navarre (age 37) succeeded II Queen Navarre.
On 23 Sep 1526 Henry Manners 2nd Earl of Rutland was born to Thomas Manners 1st Earl of Rutland (age 34) and Eleanor Paston Countess Rutland (age 31).
Letters and Papers 1535. 23 Sep 1535. R. O. 413. John Wylliamson to Cromwell.
I have received your letter by John Gresham, with seven pieces of diaper. I have been with Mr. Malete divers times concerning your livery coat, and he says the pattern of the coat for the privy chamber is not yet come, and therefore I have had a coat of "new color sad" to be made for you after my own device. I have sent your letter to Mr. Williams at Hampton Court, and he says that we shall have all that he can do in that behalf. Your works draw to an end. I have delivered to Thomas Thacker, for your buildings, &c. £100. They have been viewed by Mr. Vaghan, and, I trust, will be found as I have written. Sir Ric. a Lee, Sir John, and I are diligent in forwarding your works. One of your masons, dwelling against your great gate in Friar Austins, is sick of the plague. Three corses were buried at Hackney last St. Matthew's Day. Sir Thomas Greene is diligent. My mother and all are well. At the Rolls, 23 Sept. Signed.
P. 1. Add.: Secretary. Endd.
On 23 Sep 1571 Bishop John Jewel (age 49) died at Monkton Farleigh, Wiltshire. He was buried at Salisbury Cathedral [Map].
On 23 Sep 1584 Robert Sidney 1st Earl of Leicester (age 20) and Barbara Gamage Countess Leicester (age 21) were married. She her father's heir to his considerable fortune. He, the father, had died some twenty-five days before. The marriage took place apparently against the wishes of Queen Elizabeth I of England and Ireland (age 51).
On 23 Sep 1632 Philip Wharton 4th Baron Wharton (age 19) and Elizabeth Wandesford Baroness Wharton (age 19) were married. She by marriage Baroness Wharton.
On 23 Sep 1642 Maurice Palatinate Simmern (age 21) was wounded at during the Battle of Powick Bridge. 
Lawrence Carey (age 32) was killed.
Charles Lucas (age 29) was wounded.
John Reresby's Diary 05 Aug 1665. 05 Aug 1665. His royal highness (age 31) and his duchess (age 28) came down to York, where they stayed till September the 23rd, when the Duke (age 31) went for Oxford, where the King (age 35) was to meet the Parliament. The Duchess (age 28) went not till some time after. Most of the gentry attended at York whilst their liighnesses were there. The Duke passed his time in shooting and other exercises, the Duchess (age 28) in receiving the ladies, which she did very obligingly. One evening having a little snake (which I kept in bran in a box) in my hand as I was in the presence, one of the maids of honour seeing of it was frightened. The Duchess (age 28), hearing the noise, and what was the occasion, desired to see the snake, and took it into her hand without any fear. This Duchess (age 28) was Chancellor Hyde's (age 56) daughter, and she was a very handsome woman, and had a great deal of wit; therefore it was not without reason that Mr. Sydney (age 24), the handsomest youth of his time, of the Duke's bedchamber, was so much in love with her, as appeared to us all, and the Duchess (age 28) not unkind to him, but very innocently. He was afterwards banished the Court for another reason, as was reported.
Evelyn's Diary. 23 Sep 1680. Came to my house some German strangers and Signor Pietro, a famous musician, who had been long in Sweden in Queen Christina's (age 53) Court; he sung admirably to a guitar, and had a perfect good tenor and bass, and had set to Italian composure many of Abraham Cowley's pieces which showed extremely well. He told me that in Sweden the heat in some part of summer was as excessive as the cold in winter; so cold, he affirmed, that the streets of all the towns are desolate, no creatures stirring in them for many months, all the inhabitants retiring to their stoves. He spoke high things of that romantic Queen's learning and skill in languages, the Majesty (age 50) of her behavior, her exceeding wit, and that the histories she had read of other countries, especially of Italy and Rome, had made her despise her own. That the real occasion of her resigning her crown was the nobleman's importuning her to marry, and the promise which the Pope had made her of procuring her to be Queen of Naples, which also caused her to change her religion; but she was cheated by his crafty Holiness,43 working on her ambition; that the reason of her killing her secretary at Fontainebleau, was, his revealing that intrigue with the Pope. But, after all this, I rather believe it was her mad prodigality and extreme vanity, which had consumed those vast treasures the great Adolphus, her father, had brought out of Germany during his [campaigns] there and wonderful successes; and that, if she had not voluntarily resigned, as foreseeing the event, the Estates of her kingdom would have compelled her to do so.
Evelyn's Diary. 23 Sep 1683. There was this day a collection for rebuilding Newmarket, consumed by an accidental fire, which removing his Majesty (age 53) thence sooner than was intended, put by the assassins, who were disappointed of their rendezvous and expectation by a wonderful providence. This made the King (age 53) more earnest to render Winchester the seat of his autumnal field diversions for the future, designing a palace there, where the ancient castle stood; infinitely indeed preferable to Newmarket for prospects, air, pleasure, and provisions. The surveyor has already begun the foundation for a palace, estimated to cost £35,000, and his Majesty (age 53) is purchasing ground about it to make a park, etc.
On 23 Sep 1751 John Howe 2nd Baron Chedworth (age 37) and Martha Parker (age 35) were married.
On 23 Sep 1790 William Graham 2nd Duke Montrose (age 78) died at Twickenham. His son James Graham 3rd Duke Montrose (age 35) succeeded 3rd Duke Montrose. Caroline Maria Montagu Duchess Montrose by marriage Duchess Montrose.
On 23 Sep 1792 Charles Talbot 15th Earl of Shrewsbury (age 39) and Elizabeth Hoey Countess Shrewsbury and Waterford were married.
On 23 Sep 1814 Thomas Egerton 1st Earl Wilton (age 65) died. His grandson Thomas Grosvenor 2nd Earl Wilton (age 14) succeeded 2nd Earl Wilton, 2nd Viscount Grey de Wilton. Baron Grey Wilton 2C 1784 extinct. His fourth cousin John Grey Egerton 8th Baronet (age 48) succeeded 8th Baronet Egerton and Oulton.
On 23 Sep 1842 Henry Roper-Curzon 15th Baron Teynham (age 53) died without issue. His brother George Henry Roper-Curzon 16th Baron Teynham (age 44) succeeded 16th Baron Teynham of Teynham in Kent.
On 23 Sep 1849 James Arthur Wellington Foley Butler 4th Marquess Ormonde was born to John Butler 2nd Marquess Ormonde (age 41) and Frances Paget Marchioness Ormonde (age 32).
On 23 Sep 1857 John Townshend St Aubyn 2nd Baron St Levan was born to John St Aubyn 1st Baron St Levan (age 27) and Elizabeth Clementina Townshend Baroness St Levan.
On 23 Sep 1868 Walter Stafford Northcote 2nd Earl Iddesleigh (age 23) and Elizabeth Lucy Meysey-Thompson (age 24) were married. He the son of Stafford Henry Northcote 1st Earl Iddesleigh (age 49) and Cecilia Frances Farrer Countess Iddesleigh.
On 23 Sep 1878 Lionel Tollemache 8th Earl Dysart (age 83) died. His grandson William Tolemache 9th Earl Dysart (age 19) succeeded 9th Earl Dysart, 3rd Baronet Tollemache of Hanby Hall in Lincolnshire.
On 23 Sep 1880 George Henry Cavendish (age 70) died in Ashford Hall [Map]. He was buried in the Cavendish Plot, St Peter's Church, Edensor [Map].
George Henry Cavendish: George Henry Cavendish and Louisa Lascelles were married. She the daughter of Henry Lascelles 2nd Earl Harewood and Henrietta Sebright Countess Harewood. On 19 Aug 1810 he was born to William Cavendish (age 27) and Louisa Ocallaghan.
On 23 Sep 1880 Lucius Cary 13th Viscount Falkland was born to Byron Cary 12th Viscount Falkland (age 35).
After 23 Sep 1905. Durham Cathedral [Map]. Memorial to George Hans Hamilton (deceased).
George Hans Hamilton: On 21 Jan 1823 he was born. In 1865 George Hans Hamilton (age 41) was appointed Archdeacon of Northumberland. In 1865 George Hans Hamilton (age 41) was appointed Archdeacon of Lindisfarne which office he held until 1882. On 23 Sep 1905 George Hans Hamilton (age 82) died.
On 23 Sep 1923 Frederick Oliver Robinson 2nd Marquess Ripon (age 71) died on Dallowgill Moor Studley Royal Park having collapsed after shooting fifty-two birds that morning. Marquess Ripon, Earl de Grey, Earl Ripon, Baron Grantham, Baronet Robinson of Newby in Yorkshire 2C 1690 extinct.
On 23 Sep 1929 James George Alexander Bannerman Carnegie 3rd Duke of Fife was born to Charles Alexander Carnegie 11th Earl of Southesk (age 36) and Princess Maud Duff Countess Southesk (age 36). He a great grandson of King Edward VII of the United Kingdom.
On 23 Sep 1949 William Legge 10th Earl of Dartmouth was born to Gerald Legge 9th Earl of Dartmouth (age 25) and Raine Mccorquodale Countess Dartmouth and Spencer (age 20).
On 23 Sep 2005 John Knatchbull 7th Baron Brabourne (age 80) died. His son Norton Knatchbull 3rd Earl Mountbatten of Burma (age 57) succeeded 8th Baron Bradbourne.
