William West, 1st Baron De La Warr

William West, 1st Baron De La Warr, of the second creation (c. 1520 – 30 December, 1595), was nephew and adopted heir of Thomas West, 9th Baron De La Warr. William West was the eldest son of Sir George West, the third of four brothers, and of Elizabeth Morton, daughter of Sir George Morton of Lechlade. He was attainted, 1 February, 1550 of attempting to poison his uncle, and was deprived of all honors. His uncle died four years later, so far as we know of natural causes. William West was convicted of treason in 1556, for assisting the plot of George Dudley against Bloody Mary. (He argued that he was a peer, and should be tried in the House of Lords; but was refused.)

He was nevertheless a captain in the siege of St. Quentin in 1557. In 1563, he was restored in blood ("i.e." to his rights of inheritance by descent); he was knighted, and created Baron Delaware, on 5 February, 1570. He took part as a peer in the trials and convictions of Thomas Howard, 4th Duke of Norfolk and, later, his son, Philip Howard, 20th Earl of Arundel.

He was junior peer in his lifetime, as latest created. However, his son and descendants have been seated with the precedence of 1299, as though they had inherited his uncle Thomas's title. By the modern rules of the House of Lords, his uncle's title fell into abeyance between the daughters of William West's second uncle, Sir Owen West, or their heirs; however, as Cokayne notes, such rules are at best modern approximations to actual medieval practice. What seems clear is that some, but not all, writers treat the letters patent as clarifying the descent of the ancient title, rather than creating a new one, hence William is sometimes referred to as 10th baron.

"Style: In this article days of the year are Julian; but the year is counted as beginning January 1."