Died from poisoning is in Murder.
On 19 Dec 966 Sancho "Fat" I King Leon (age 34) died from poisoning. His son Ramiro III King Leon (age 5) succeeded III King Leon.
On 16 Dec 1153 Ranulf Gernon 4th Earl Chester (age 54) died from poisoning by William "The Younger" Peverell (age 73). His son Hugh de Kevelioc Gernon 5th Earl Chester (age 6) succeeded 5th Earl Chester 2C 1071. William "The Younger" Peverell (age 73) was exiled.
On 20 Jul 1304 Hugh Mortimer 3rd Baron Mortimer (age 49) died from poisoning. He was buried in Worcester Cathedral [Map]. He was succeeded by his daughter Joan Mortimer Baroness Talbot
His Matilda Unknown Baroness Mortimer was suspected. She sought the protection of Margaret of France Queen Consort England (age 25). After the death of King Edward "Longshanks" I of England (age 65) in 1307 she, Matilda Unknown Baroness Mortimer died suddenly, probabnly murdered in revenge for the murder of her husband.
On 27 Aug 1312 John Ferrers 1st Baron Ferrers of Chartley (age 41) died from poisoning. His son John Ferrers 2nd Baron Ferrers of Chartley (age 4) succeeded 2nd Baron Ferrers of Chartley.
On 07 Oct 1368 Lionel Plantagenet 1st Duke of Clarence (age 29) died from poisoning at Alba [Map]. Duke Clarence 1C 1362 extinct. There was strong speculation he had been poisoned by his wife's (age 14) father (age 48). He was buried at Clare Priory [Map]. His daughter Philippa Plantagenet Countess March 5th Countess Ulster (age 13) succeeded 5th Countess Ulster.
On 20 Jul 1387 Robert IV Artois Count Eu (age 31) died from poisoning.
In 1425 John "Pitiless" Wittelsbach II Duke Bavaria Straubing (age 50) died from poisoning. His uncle Otto "The Bavarian" Wittelsbach V Duke Bavaria succeeded V Duke Bavaria.
In 1501 sisters Margaret Drummond (age 26), Eupheme Drummond and Sibylla Drummond died from poisoning, food poisoning, at Drummond Castle.
On 16 Apr 1594 Ferdinando Stanley 5th Earl of Derby (age 35) died from poisoning. His brother William Stanley 6th Earl of Derby (age 33) succeeded 6th Earl Derby 3C 1485. Baron Stanley 1C 1456 abeyant.
On 14 Sep 1613 Thomas Overbury (age 32) died from poisoning at the Tower of London [Map].
On 06 Nov 1656 Robert Shirley 4th Baronet (age 33) died from poisoning, probably, in the Tower of London [Map]. His son Seymour Shirley 5th Baronet (age 9) succeeded 5th Baronet Shirley of Staunton Harold in Leicestershire.