Edmund Denison, the son of Lord Grimthorpe was born at Carlton Hall, near Newark in 1816. After being educated at Eton and Trinity College, Cambridge, he became a lawyer. In 1845 Denison was appointed parliamentary counsel for the Great Northern Railway (GNR). Denison's family were closely associated with the GNR. He father, Lord Grimthorpe, was chairman (1847-64), and his brothers, Christopher and William, were both directors of the company.

As parliamentary counsel, Edmund Denison was also involved in promoting the line that linked the Great Northern Railway with the Liverpool & Manchester Railway in 1865 and the GNR's Derbyshire & Staffordshire Bill in 1872.

Denison took a keen interest in architecture and was involved in the restoration of St Albans Abbey and the designing of a new casement for Big Ben. Edmund Denison, who inherited his father's title in 1886, died in 1905.