The name given to the British practice of taking American sailors from their ships and forcing them to serve in the British Navy is "impressment". There are also colloquial expressions: "the press" and "the press gang". It was used by the Royal Navy in wartime, beginning in 1664 and during the 18th and early 19th centuries as a means of crewing warships, although legal sanction for the practice goes back to the time of Edward I of England. Impressment was strongly criticized by those who believed it to be contrary to the British constitution.