Lord Cranborne was selected as the Conservative Party candidate for South Dorset in 1976, where his family owned land, despite there being on the shortlist several former members of parliament who had lost their seats in the two 1974 elections.

He won the South Dorset seat at the 1979 general election, becoming the seventh consecutive generation of his family to sit in the House of Commons.

He took an interest in Northern Ireland, and, when Jim Prior announced his policy of 'Rolling Devolution', resigned an unpaid job as assistant to Douglas Hurd.

Lord Cranborne became known in the early 1980s as an anti-communist, as a supporter of Afghan refugees (from the Soviet invasion of that country) in Pakistan, and for sending food parcels to Poland.

Until the early years of the 21st century, a charity shop was run on his Hatfield House estate solely to raise money for these causes, including funds for Polish orphanages.

He was recognised as one of the few members of the Cabinet who were personally loyal to Major, but continued to lead the Conservative Peers after Labour won the 1997 general election.

In January 2010, Lord Salisbury and Owen Paterson, the Shadow Secretary of State for Northern Ireland, hosted secret talks at Hatfield House, involving the DUP, the UUP and the Conservative Party.

These talks prompted speculation that the Conservatives were attempting to create a pan-unionist front to limit Sinn Féin and the Social Democratic and Labour Party at the 2010 general election.

The book was privately published as a contribution to the Roxburghe Club, and is illustrated by a set of sketches by Simpson, now owned by Lord Salisbury.

The Cecils are landowners in Dorset, Hertfordshire and London, and the 7th Marquess ranked 352nd in the Sunday Times Rich List 2017, with an estimated net worth of £335m (of which the paintings at Hatfield accounted for £150m).

The Marquess of Salisbury's heir is his elder son Robert Edward "Ned" William Gascoyne-Cecil, Viscount Cranborne (born 1970).