Begun in August, 1415, by the English army commanded by Henry V, the Siege of Harfleur was, in effect, the opening salvo of Henry's invasion of France. It was the first time that an English army had made significant and effective use of artillery in the siege of a large settlement. When the French crown was unable to raise a force in time to defend the city, Harfleur surrendered to Henry's forces on September 22, 1415.