Bertram Denison was born into a Canadian family with a long tradition of military service. His great-grandfather, grandfather, father, and his uncles, all served in the army or militia. Initially Bertram followed his father, Rear Admiral John Denison, into the Royal Navy, seeing service as a midshipman aboard HMS Doris during the Boer War. Denison served as an aide de camp to Captain John Edward Bearcroft, and played a role in escorting Boer general Piet Cronjé and his wife to internment in St. Helena, after his surrender. Denison was mentioned in dispatches.
Denison was wounded in the head, and left for dead during the Battle of Le Cateau, described as the first battle of World War One. Denison was, initially, able to still direct his men, after his wound, as his battalion tried to hold their position, allowing nearby battalions to retire. But he gradually faded into unconsciousness. 600 of the 1000 men in his battalion were casualties that day.
German soldiers took him prisoner, after he had been lying wounded on the battlefield, for more than a day. A French woman who nursed Denison would tell his parents, after the war, that he was struck behind his left ear. He had a black eye, but his face was not otherwise disfigured. His wound caused him to go blind, but he wasn't paralyzed, and remained coherent and did his best to cheer up the other wounded prisoners. A German doctor operated on him, but did not remove the bullet, or shrapnel. It was thought he might recover from his wound, until he was struck by tetanus, nine days after the operation.
- Paul Hunter (2014-09-08). "Toronto’s first casualty of World War 1". https://www.thestar.com/news/world/ww1/2014/09/08/torontos_first_casualty_of_world_war_i.html. Retrieved 2019-06-09. "Blinded by a bullet that ripped into his skull, Denison was left for dead in the early morning hours at the battle of Le Cateau — part of a British retreat from Mons, Belgium — on Aug. 26, 1914. There, on the blood-soaked killing fields of northern France, amid the carcasses of men and horses, the dashing Lt. Denison lingered in the unbearable summer heat. He remained through the rest of the day, that night and into the next day before he was taken prisoner by the Germans, who transported him first to a church for three days, then to a makeshift hospital."
- David Gagan (1973). The Denison Family of Toronto: 1792-1925. University of Toronto Press. ISBN 9781487597368. https://books.google.ca/books?id=ZPs2DwAAQBAJ&pg=PT22&lpg=PT22&dq=%22George+Taylor+Denison%22+1783+OR+1853&source=bl&ots=QxGLpGYsY4&sig=ACfU3U2AJF0i_PW67sQ8b-PIOF323aDRRA&hl=en&sa=X&ved=2ahUKEwjh79v07driAhVoRN8KHbC4DfYQ6AEwFHoECE4QAQ#v=snippet&q=george&f=false.
- "Bertram Noel Denison". Inverclyde's Great War. http://www.inverclydeww1.org/honour-roll/bertram-noel-denison. Retrieved 2019-06-11. "Born, Greenock, Scotland, on 21 December 1883, the son of Rear-Admiral John Denison of Toronto, Canada, and Florence Ledgard of Yorkshire. Bertram was educated at Harrow and sandhurst and passed first on the list from HMS Brittania, in December 1898. Served Boer War (Midshipman, HMS Doris) with the Naval Brigade as ADC to Captain Bearcroft: operations in Transvaal, Belfast and Orange Free State. Was mentioned in a despatch, 12 March 1901."
- "Name Denison, Bertram Noel Date of Birth: 21 December 1883 Rank: ...". UK National Archives. https://discovery.nationalarchives.gov.uk/details/r/D7603970. Retrieved 2019-06-11.
- "...landing the Boer general Cronje on the island of St. Helena after the latter's defeat and capture. The 13 June, 1900 edition of The Straits Times quotes a personal letter from Denison". Soldiers of the Queen. Archived from the original on 2019-06-11. http://www.soldiersofthequeen.com/SouthAfrica-BertramNoelDenison.html. Retrieved 2019-06-11. "After attending staff college (1912-13) he received a staff appointment at the War Office though with the outbreak of World War One he immediately rejoined his regiment."