There is no such person as Lord Lavendon, however, his character is based upon all those noble Lords of the Realm, who have led and protected England since time began- the inspiration being the likes of the Magna Carta Barons, Robin Hood, Wellington, Marlborough and Palmerston.
The author also has a personal website, which if you are interested can be visited here : http://aldridge2lavendon.blogspot.com/