If the defendant does not know he is breaking the law, his mistake will not help him avoid liability. Hence, the saying 'Ignorance of the law is no excuse'. This is the case even if D's ignorance is quite reasonable, and even if it were impossible for him to know of the prohibition in question. In R v Bailey (1800) Russ & Ry 1 D was convicted of an offence created by a statute when he was on the high seas. He committed it before the end of his voyage when he could not possibly have known of the statute.