Henry Allen came to Gloucester from Stroud with the late Alderman Joseph Reynolds in 1860, to begin operating the City Flour Mills. The Gloucester City Flour Mills had been operated by Joseph and Jonah Hadley since 1850. Henry Allen and Joseph Reynolds passed on the business in 1875 to their sons, John Allen and Vincent Reynolds, in partnership with Francis Tring Pearce. Henry Allen retired from the mills in about 1878 and the firm later became Priday, Metford and Company Limited. His daughter Martha Allen married Francis Tring Pearce, thus affirming the family nature of the business.