White and Poppe Limited owned a Coventry proprietary engine building and gearbox manufacturing business established in 1899. Many early motor vehicle manufacturers making only a small number of vehicles bought in their major components and White and Poppe soon had a large customer base and by 1914 a staff of around 350 people. By then the number of these customers, once as high as 15 or more, had fallen away though not the production volume leaving Dennis Brothers, always an important customer, taking much of their output.