He was the eldest son of warehouseman and haberdasher Joseph Brooksbank of Hackney House and Cateaton St., Cheapside, London. He was the heir of his mother's father Richard Stamp, the elder brother of Sir Thomas Stamp, Lord Mayor of London in 1692. He became a successful merchant trading with Turkey and was a member of the New England Company in 1726. He succeeded his father in 1726 to Healaugh Manor, near Tadcaster, Yorkshire.
He was elected MP for Colchester in 1727 and for Saltash in 1743, being re-elected for the same constituency in 1747. He was a director of the Bank of England from 1728 to 1740 and from 1743 to 1755, as deputy governor from 1740 to 1741 and as governor from 1741 to 1743.
He built Hackney House in Clapton in 1732. He had married Elizabeth, the daughter of Joseph Thomson of Hackney and Nonsuch Park, Surrey with whom he had 3 sons and 5 daughters. He was succeeded by his son Joseph.
