Pacific blockade was a term invented by Hautefeuille, the French writer on international maritime law, to describe a blockade exercised by a great power for the purpose of bringing pressure to bear on a weaker state without actual war. It is usual to refer to the intervention of France, England and Russia in Turkish affairs in 1827 as the first occasion on which the coercive value of pacific blockades was put to the test. Neutral vessels were not affected by it. This was followed by a number of other coercive measures described in the textbooks as pacific blockades.