Delaval belonged to one of Northumberland’s oldest gentry families. His forbears settled at Seaton Delaval, in the south-east of the county, as early as Henry II’s reign, and first provided a knight of the shire in 1373.
Delaval himself, although a younger son, was relatively well provided for by his family. In 1600 his father granted him a life interest in the manor of North Dissington, roughly 12 miles south-west of Seaton Delaval, while Ralph simultaneously leased him another estate in the same area. This property was augmented by the purchase of South Dissington manor eight years later.
Now firmly established as one of Northumberland’s most authoritative voices, Delaval was elected a knight of the shire in 1626. As a novice at Westminster, however, he made little impact on the Commons’ proceedings, never speaking (so far as is known) and attracting nominations only to legislative committees concerning the marshlands of Canvey Island, Essex, and the estates of Sir Timothy Hutton, a relative of his first wife (28 Mar. and 11 May). In his capacity as a Northumberland Member, he may also have helped to prepare the presentment of recusants in Newcastle and County Durham (21 February).
Delaval’s record of conscientious public service continued through his later career. As a deputy lieutenant in 1628, he cooperated with the unpopular militia reforms then being introduced in Northumberland. In February 1629 he was appointed by the House of Lords to investigate complaints that Lord Grey of Warke (Sir William Grey*) had been slandered by a Newcastle man.
During the Bishops’ Wars Delaval was one of the handful of Northumberland deputy lieutenants trusted by the government.
