Harpur came from a medieval Staffordshire family that produced a knight of the shire in 1419. His father acquired Swarkeston, situated on the Trent five miles south of Derby, by marriage, became a judge under Elizabeth,
As Derbyshire’s lord lieutenant, Shrewsbury twice secured Harpur’s return for the county. Shortly after the second occasion, in 1604, it was reported that Shrewsbury had helped Harpur court a wealthy widow, Lady Wortley, but in the event she married Sir William Cavendish†.
Harpur’s absence from the opening of the second session was alleged as evidence of his patron’s foreknowledge of the Gunpowder Plot,
Harpur developed an appetite for litigation, mostly against his tenants.
