Early years and family
John was born in Atholl, Perthshire, Scotland around 1266. He was the son of David I Strathbogie, Earl of Atholl (d. 1270), by his spouse Isabel, daughter of Richard de Dover, Baron of Chilham, Kent. John de Strathbogie first appears on record as his father's son and heir in 1282. He was a great-great-grandson of King John of England through an illegitimate line. Descendants of King John are shown below:
- King John of England + Adela de Warenne (Concubine)
- Richard FitzRoy
- Richard de Dover, Lord of Chilham
- Isabel de Dover
- John Strathbogie, 9th Earl of Atholl
Life and military service
In 1284, he joined with other Scottish noblemen who acknowledged Margaret, Maid of Norway, as the heir presumptive to King Alexander III. In 1296, he fought on the Scottish side at the Battle of Dunbar, where he was captured and sent to the Tower of London. After a year's confinement there he was set free on condition that he served King Edward I of England in Flanders.
He did homage for his manor of Lesnes, Kent, in 1305 but subsequently returned to Scotland, and in 1306 joined Robert the Bruce in his rising against English overlordship, and his English possessions were forfeited. He took part in Robert's coronation in that year.
In the subsequent English invasion of Scotland in 1306, he was taken prisoner at the Battle of Methven. John, Earl of Atholl, was hanged in London on 7 November 1306, on a gallows 30 feet higher than ordinary. This was to signify his higher status than his fellow prisoners: no earl had been executed in England for 230 years. His body was burnt and his head fixed on London Bridge.
Marriage and children
- David de Strathbogie, 10th Earl of Atholl (d. 28 December 1326)
- Sir John de Strathbogie, Knight.
- Isabel, wife or mistress of Edward de Brus, Earl of Carrick.
- "Ancestors and/or relations of John DE STRATHBOGIE 9th Earl of Atholl". Retrieved 5 November 2011.
- "John of Strathbogie, 9th Earl of Atholl". geni_family_tree. Retrieved 30 August 2019.
- Foedera, p228
- Lewis, Marlyn. "John of Strathbogie, 9th Earl Atholl". Our Royal, Titled, Noble, and Commoner Ancestors & Cousins. Retrieved 5 November 2011.
- Rymer, Thomas,Foedera Conventiones, Literae et cuiuscunque generis Acta Publica inter Reges Angliae. London. 1745. (Latin) 
- Richardson, Douglas, Plantagenet Ancestry, Baltimore, Md., 2004, p. 50, ISBN 0-8063-1750-7