Jennings succeeded his father, Sir John Jennings, as head of the family in August 1642, and took residence at Sandridge in Hertfordshire. His mother was Alice, daughter of Sir Richard Spencer of Offley, who bore his father no less than 22 children. He was also elected as Member of Parliament (MP) for St Albans in succession to his father in 1642. History of Parliament Online - Jennings, Richard
