Background
Slingsby was the fourth, but ultimately eldest surviving son of Sir Francis Slingsby of Scriven and his wife Mary Percy, sister of Henry Percy, 8th Earl of Northumberland.
Slingsby was the fourth, but ultimately eldest surviving son of Sir Francis Slingsby of Scriven and his wife Mary Percy, sister of Henry Percy, 8th Earl of Northumberland.
He held a number of offices including feodary for the Duchy of Lancaster and feodary of Tickhill. He was receiver of Pontefract Castle, and was receiver surveyor and collector of Knaresborough and Wakefield in 1588. He was janitor and deputy keeper of Knaresborough Castle and bailiff and coroner within the liberty of Knaresborough.
He was chief forester of Knaresborough and Wharfdale and was custodian of Bilton park in about 1600.
He succeeded to the estates of his father in 1600. He was also Justice of the Peace for the West Riding of Yorkshire in 1601.
He was knighted in 1602. In 1604, he was re-elected Member of Parliament for Knaresborough.
He was Sheriff of Yorkshire from 1611 to 1612.
In 1614 he was elected Member of Parliament for Knaresborough again and was re-elected in 1621 and 1624. Slingsby died at Nun Monckton, Yorkshire, at the age of about 74 and was buried on 28 December in the family chapel in Knaresborough church.
Happy Parliament; Addled Parliament]
In 1601, Slingsby was elected Member of Parliament for Knaresborough. From 1603 he was a member of the council in the north.