'Sergeant Wilde' is Sir Thomas Wilde, 1782-1855, Lord Chancellor, from 1850 1st Baron Truro. As a young man he had distinguished himself at the trial of Queen Caroline in 1820 and was chosen one of her executors. He became a sergeant-at-law in 1824 and in 1827 king's sergeant. In 1839 he was solicitor-general. Russell is Home Secretary.Licences such as these were required, for example, when a high ranking barrister was to appear in a case normally handled by a barrister of lower rank, perhaps when he himself had been promoted during the proceedings, or took a special interest in the case.