Formerly, the rank of king's counsel not only precluded a barrister from appearing against the Crown, but, if he was a member of parliament, entailed that he give up his seat.
A patent of precedence was resorted to as a means of conferring similar marks of honour on distinguished counsel without any such disability attached to it.
The patents obtained by Mansfield, Erskine, Scott, Jervis and Brougham were granted on this ground.
[1] After the serjeants-at-law lost their exclusive right of audience in the Court of Common Pleas, it became customary to grant patents of precedence to a number of serjeants, giving them rank immediately after KCs already created and before those of subsequent creation.
Mr Justice Phillimore was, on his appointment as a judge of the queen's bench division (in 1897) the only holder of a patent of precedence at the bar, except Serjeant Simon, who died in that year, and who was the last of the serjeants who held such a patent.