Robert Cecil, 1st Earl of Salisbury, KG, PC was an English administrator and politician. He was the younger son of William Cecil, 1st Baron Burghley by his second wife Mildred Cooke. His elder half-brother was Thomas Cecil, 1st Earl of Exeter, and the philosopher Francis Bacon was his first cousin.
Following the resolution of the succession dispute between the daughters of Ferdinando, Earl of Derby and their uncle, William, Earl of Derby, it was ruled that the daughters of Ferdinando were the rightful heirs to the title of Lord of Mann. As the oldest of them would not reach the age of majority until 1609, two temporary Lords of Mann were appointed by James I, using letters patent, so that the daughters could benefit from the Island's revenues. The second of them was Robert Cecil, 1st Earl of Salisbury.