[1] On the resignation of Sir William Henry Ashurst, 9 June 1799, Le Blanc was appointed to succeed him as puisne judge of the king's bench, and knighted.

He showed his independence of mind in the case of Haycraft v. Creasy (2 East 92), where he differed from Lord Kenyon, on a point of law which the latter had long treated as established.

For his part in two trials for murder on the high seas, which had terminated in acquittals in December 1807 and January 1808, he was charged in the Independent Whig with perverting justice out of mistaken humanity; though.

[1] At the Lancaster spring assizes in 1809 Joseph Hanson, a gentleman of property, was indicted before Le Blanc for a misdemeanour in abetting the weavers of Manchester in a conspiracy to raise their wages.

[1] Le Blanc died unmarried on 15 April 1816 at his house in Bedford Square, and was praised by the reporters George Maule and William Selwyn, in recording the fact.