Baron Arundell of Wardour, in the County of Wiltshire, was a title in the Peerage of England. It was created in 1605 for Thomas Arundell, known as "Thomas the Valiant", son of Sir Matthew Arundell (died 1598) and grandson of Sir Thomas Arundell (executed 1552) and of Margaret Howard, a sister of Queen Catherine Howard. Arundell had already been created a Count of the Holy Roman Empire by Rudolph II in December 1595 (see below). He was succeeded by his son, the second Baron. He fought as a Royalist in the Civil War and was mortally wounded at the Battle of Stratton in 1643. His son, the third Baron, was implicated in the Popish Plot and imprisoned in the Tower of London for six years. However, after the accession of James II he was restored to favour and served as Lord Privy Seal from 1687 to 1688. His great-great-great-grandson, the eighth Baron (the title having descended from father to son), was an avid collector of art and accumulated immense debts in building and furnishing New Wardour Castle.