DLA Piper joint chief executive Nigel Knowles has been made a knight of the realm after being named in the New Year Honours List.
London-based Knowles, who in 1998 was made managing partner of Yorkshire firm Dibb Lupton Broomhead and now heads the world's largest firm by number of lawyers, was knighted for services to the legal profession.
Peter Wayte, DLA Piper senior partner, said: "We believe this recognises his truly exceptional service to the legal profession, both in terms of his leadership within DLA Piper and the role he's played in driving the responsible business agenda, particularly in the area of climate change."
Knowles was praised by Prince Charles in December at the launch of the Legal Sector Alliance's initiative to combat global warming for his commitment to the cause.
During his reign at DLA Piper, he has overseen a number of significant mergers, including the tie-up with US firms Piper Rudnick and Gray Cary Ware & Freidenrich.
Also named in the honours list is David Lewis, former senior partner of Norton Rose who served as Lord Mayor of the City of London between 2007 and 2008. He was knighted for services to the City as well as to the legal profession.