Wilhelm Nero Pilate Barbellion was the pen name of Bruce Frederick Cummings (7 September 1889 – 22 October 1919), an English diarist who was responsible for The Journal of a Disappointed Man.

Having begun his journal at the age of thirteen, Cummings continued to record his observations there – gradually moving from dry scientific notes to a more personal, literary style.

Despite an obvious passion for the subject from an early age, Cummings, upon the advice of others, followed his father and Brother (Arthur John) into the world of journalism, which he hated, as he often mentioned in his diary.

[3] Hurt, Cummings decided to open the letter on his way back home to see what had been inside, and was staggered to learn that his doctor had diagnosed him with multiple sclerosis, and that he almost certainly had less than five years to live.

[5] The Journal of a Disappointed Man, filled with frank and keen observation, unique philosophy and personal resignation, was described by its author as "a study in the nude".

The strong early sales and the admiration received by The Journal of a Disappointed Man are largely forgotten by the wider reading public today, but the book has been frequently reprinted in paperback and is regarded as a classic of English literature.