Sir William Cecil, 17th Baron de Ros (May 1590 - June 27, 1618)
He was born at Newark Castle, Nottinghamshire, and baptized on June 4, 1590. In 1591, he inherited the barony of de Ros from his mother, Elizabeth Cecil, 16th Baroness de Ros. On February 13, 1615, he married Ann Lake.
The title of BarondeRos (pronounced "Roose") is the most ancient baronial title in the Peerage of England.
The title was originally held by the deRos family until the death of the eleventh Baron in 1508, when it was inherited by his nephew, Sir George Manners.
Upon the death of Elizabeth's only son, WilliamCecil, the title returned to the Manners family, being inherited by the sixth Earl of Rutland.