The Delaval family is a notable English family with historical significance, particularly in the 18th and 19th centuries. They are best known for their contributions to agriculture and engineering, especially through the work of Sir William Delaval, who was a prominent figure in the development of steam power and agricultural machinery. Members of the Delaval family were also involved in politics and land management, owning substantial estates in Northumberland. Their legacy includes advancements in farming techniques and machinery that have had a lasting impact on the agricultural industry.