"Lord" Buckingham

I'm a bit confused by this recent case of a man who adopted the name of someone who had died in infancy, and created a new identity - including a title - for himself based on that name (anyone who has read "Day of the Jackal" will be familiar with the idea). He's recently been up in court, and been sent down for 21 months - but for what? I can only assume it is for making a false declaration on an application for a passport, because otherwise I am not aware of any law which prevents you calling yourself whatever you want, provided you do not do so in order to defraud, and there does not appear to be any indication that this man gained any pecuniary advantage from his deception. He may have something to hide, or he may simply be several sandwiches short of a picnic, but he does seem to have been treated rather harshly in proportion to his offence.