He was born on 24th June 1895 at Eastfield Side, Sutton-in-Ashfield. His parents were Samuel & Elizabeth Slack. Samuel Slack was a Framework Knitter, who died sometime before 1916. At the time of his death his mother had remarried as Elizabeth Dove, and  was living at 52 York Street, Sutton-in-Ashfield, Nottingham. He enlisted at Nottingjham.

Notts Free Press - In Memoriam - 27th September 1918

Slack - In Ever-Loving memory of Lance-Corporal Herbert William Slack, who was killed in Action, September 27th 1916. "May his reward be greater than his sacrifice" - From his ever-loving Mother. 

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