Hanbury’s father, a Northamptonshire country gentleman descended from the Hanburys of Hanbury, inherited the estates of the Bateman family in 1802. His grandfather twice contested Northampton. He himself was returned for the borough unopposed on the independent interest on a vacancy in 1810. He succeeded a staunch Whig, Edward Bouverie, in the seat. His own politics, so he confessed to his constituents’ after his election ‘as the glass went round’, were the same.
Hanbury demonstrated his bias by his votes during the Regency debates. He could not be rallied to an extra-parliamentary meeting of Friends of Constitutional Reform. On 6 June 1811 he opposed the restoration to office of the Duke of York. He was a staunch supporter of Catholic relief in both of his Parliaments. He voted for the critical opposition motions of 4 and 27 Feb. 1812. On behalf of his constituents’ he opposed the additional leather tax, 26 June, 2 July 1812 and 9 May 1816. He was in the minority on the vice-chancellor bill, 11 Feb. 1813. He refused to support his constituents’ petition against the corn bill and stayed away. In an apologia of 24 Mar. 1815, he pointed out that his colleague Earl Compton, who had agreed to present the petition, had voted against the prayer thereof. In a huff, he declared that he would not offer at the next election.
Hanbury unsuccessfully contested the northern division of Northamptonshire in 1832 and December 1835. He died a Whig peer, 22 July 1845.