According to his attestation papers dated March 21, 1916 at Toronto, Harold Lambert of Algoma Street, Mimico was born on May 9, 1895 at Brighton, England. He listed his mother Jemima Lambert, Algoma Street, Mimico as his next of kin. He listed his occupation as brass caster and indicated that he was a member fo the 12th Regiment. He was 20 years and 10 months of age and stood 5 feet 10 inches tall. He had blue eyes, light hair and a fair complexion. He was a member of the Church of England.
He was a Sapper.
He enlisted on the same day with his brother Wallace who was also a Sapper.