Sidney was born at
Baynard's Castle in London, the son of
Robert Sidney, 1st Earl of Leicester, and his first wife,
Barbara Gamage. He was educated at
Christ Church, Oxford. In 1610 he was created Knight of the Bath when Prince Henry was created Prince of Wales. He was elected
Member of Parliament for
Wilton in 1614. He was elected one of the two
knights of the shire for
Kent in 1621. In 1624 he was elected as the member for
Monmouthshire and was re-elected for that county in 1625. In 1626, he succeeded his father as Earl of Leicester. In 1631, he began the construction of
Leicester House, a huge mansion on the site of what is now
Leicester Square in London. The Crown employed him on a diplomatic mission to
Denmark–Norway in 1632 and undertook further diplomatic work in France from 1636 to 1641. Lord Leicester was then appointed
Lord Lieutenant of Ireland in place of
The Earl of Strafford. When the governorship of
Dublin became vacant, Leicester appointed
George Monck.
Charles I, however, overruled the appointment in favour of
Lord Lambart. In 1643 he resigned without having set foot in Ireland. Lord Leicester died at
Penshurst at the age of nearly 82. He was "esteemed of great learning, observation and veracity". ==Family==