Bertie was born in 1674, the second son of James Bertie, 5th Baron Norreys, later created Earl of Abingdon, and his wife Eleanor Lee, the elder daughter of Sir Henry Lee, 3rd Baronet and his wife Ann Danvers.
In 1714, he became a Commissioner for the Trent navigation, and also steward of Grosmont, Skenfrith and White Castle in the Duchy of Lancaster, a post he held until 1720.
[3] Although the Stanwell estate passed to Lord Falkland upon his wife's death that year, Bertie's personal electoral influence in Middlesex remained strong.
[5] He and Francis Annesley, also standing on the Bertie interest,[6] were returned in place of the sitting members, Lord Carbery and Charles Allanson;[5] while Carbery and Allanson had a better claim to the seat, their election petition was disqualified on technical grounds.
[5] On 2 December 1724,[a] Bertie seconded a motion by John Barnard for a committee to inquire into the crimes committed in Wapping,[3][7] where debtors fleeing bailiffs had gathered and terrorised the neighbourhood after the abolition of their former sanctuaries.
[9] Some time after his first wife's death in 1715, Bertie married Elizabeth Calvert, the daughter of Rev.