HMS Merlin was an 8-gun yacht of the Royal Navy, best known for its use as a pretext for the 1672 to 1674 Third Anglo-Dutch War. In August 1671, Lord Arlington ordered Merlin, carrying the English ambassador's wife Dorothy Osborne, to pass Dutch ships anchored near Brill; as agreed by treaty, the Dutch struck their flag in salute but failed to fire white smoke, a courtesy given to warships. Dutch commander Van Ghent later explained he was doubtful as to whether the Merlin came into that category and did not want to create a precedent.