Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the son of Mordecai Cook a plaster miller, born 1857 in Kegworth, Leics., and his wife Mary Ann, born 1860 in Cotgrave, Notts. John was born in 1890 in Kegworth, Leics., his siblings were, Elizabeth, born 1882, Alice, born 1884, Mordecai, born 1885 and Emily, born 1887, all his siblings were born in Kegworth, Leics., in April 1891 the family home was at Nottingham Road, Kegworth, Leics. In March 1901 John was residing in the family home at Boro Street, Kegworth, Leics., together with his parents and siblings, Elizabeth, Alice, Mordecai, Emily, Sarah, born 1894, Joseph, born 1899 and Ted, born 1901, the latter three siblings were all born in Kegworth, Leics. In April 1911 John was employed as a shop assistant and was residing in the family home at Bridge Lane, Kegworth, Leics., together with his parents and siblings, Alice, Sarah, Joseph and Ted. In the April, May, June quarter of 1912, John married Ethel Brookes in the Shardlow, Derbyshire marriage registration district.