Source: 18th Battalion Nominal Roll, April 1915.
Biography relates his belief he was a baronet.
Brother served in C.E.F. Edward Filmer, reg. no. 1069624.

“
Note: He initially joined the Royal Engineers but then emigrated to Canada. In the 1914-18 war, he served overseas but was invalided out. (National Archives of Canada) Ref. RG 150, Acc 1992-93/166, Box 3080-63. Regimental No. 53190
He was attested into the Canadian Overseas Expeditionary Force at Windsor [Canada] on 1/11/1914. At that date he had had 3 years previous experience in the RE [Royal Engineers].
His address was given as 3 Old Queen St, London, on 12/3/1917, when his brother Edward was attested into the CEF.
His father was always convinced that he was fairly closely related to the Filmer baronets and told his son that he would suceed to the Filmer baronetcy in due course. His father's contention coloured his later actions.
He married twice: first to Florence Eveleigh Relleen, the daughter of a government contractor, William Relleen. The marriage certificate is of interst:
'St. Margaret, Westminster. No. 80.
George Bertram Filmer 33 Bachleor Baronet Technical Engineer
3 Old Queen Street. SW Father George Budds Filmer (deceased). Gentleman
Florence Eveleigh Relleen 33 Spinster
3 Old Queen Street. SW Father William Relleen (deceased) Government Contractor.
By banns.
In the presence of: Jane Relleen and Frederick Simpson.
Married by H.F. Westlake, Minor canon of Westminster.
Book No. 22. 16th August, 1917.'
It will be noticed that he was stated to be a baronet and, presumably, thought he had become so on the death of the last Filmer baronet in 1916. Indeed he was known as Sir George Filmer for most of his life, sometimes to the embarassment of ot hers.
They lived in Canada, where his only child was born.
He became a quite well known chemical engineer and prospector, travelling widely throughout the United States and Canada. He continued to live at Raycroft, and used his home as a base for investigating the coal resources of Canada. He late r moved to 157 Bowood Avenue, Toronto.
He married for the second time, Margaret Gertrude Victoria Filmer, the daughter of William Charles Blackman Filmer and Margaret (Long) of Brunswick Street, Maidstone:
'Marriage Certificate.
I hereby certify that on the 3rd day of February, 1925 the rite of Holy Matrimony was solemnized by me, by authority of Licence between George Bertram Filmer Bt. of the City of Toronto, Province of Ontario, Dominion of Canada, and Queenie Gertru de Filmer of the City of Toronto, Province of Ontario, and Dominion aforesaid.
Witness my hand at Toronto this 3rd day of February, 1925.
In the presence of Effie A. Partridge, Eli E. Lent.
Officiating Minister: S.P. Addison.'
At the date of his aunt, Mary Ann Filmer's will (codicil), in 1941, he was stated as being resident at 25 Cranbrook Avenue, Toronto, Canada.
During the latter part of his life, he spent much time trying to prove that he was, in fact, the heir to the Filmer baronetcy. Towards the end, however, he realised that he had been misled by his father.
Christening: Bowdon, Cheshire
Occupation: Place: Auto driver (1914)
Religion: Place: C of E (1914)
Death: 15 JUL 1953 Toronto, Ontario, Canada
Change: Date: 28 NOV 2001"
http://www.kevyoung.com/familytree_files/n_218.html
“George Bertram FILMER was bor on 6 Jan 1884 at Charlton-cum-Hardy, Withington USD, Lancashire & died in Toronto Canada on 15 July 1953. He was attested into the Royal Engineers as a driver on 31 July 1906, attestation no. 15944, at the age of 22 years 6 months. His trade was that of a fitter and turner.He agreed to serve for twelve years, of which the last 9 years were in the reserve. He was posted as a Sapper on 15 Aug 1906 and as a Lance Corporal (unpaid) on 22 Feb 1908. He was granted his 1st Good Conduct Badge on 31 Jul 1908. He was then discharged, at his own request, on payment of £18, on 25 Aug 1908. His next of kin was his younger brother, Edward, of 9 Esmond Road, Cheetham. He departed from Liverpool for Quebec on 14 July 1910, and was described as single and a labourer. He arrived in Canada on 21 Jul 1910, aged 26, with his brother Edward, onboard the CORSICAN. In the 1914-18 war, he served overseas but was invalided out. (National Archives of Canada) Ref. RG 150, Acc 1992-93/166, Box 3080-63. Regimental No. 53190 He was attested into the Canadian Overseas Expeditionary Force at Windsor [Canada] on 1/11/1914. At that date he had had 3 years previous experience in the RE [Royal Engineers]. Service No. 53190”
https://livesofthefirstworldwar.iwm.org.uk/story/86488


