Historical examples of flanking maneuvers  In military tactics, a flanking maneuver, or flanking manoeuvre (also called a flank attack), is an attack on the sides of an opposing force. If a flanking maneuver succeeds, the opposing force would be surrounded from two or more directions, which significantly reduces the maneuverability of the outflanked force and its ability to defend itself. Flanking maneuvers played an important role in nearly every major battle in history, and have been used effectively by famous military leaders like Hannibal, Julius Caesar, Khalid ibn al-Walid, Napoleon, Saladin, Nader Shah, William Tecumseh Sherman and Stonewall Jackson throughout history. Sun Tzu's "The Art of War" strongly emphasizes the use of flanking, although it does not advocate completely surrounding the enemy force as this may induce it to fight with greater ferocity if it cannot escape. A flanking maneuver is not always effective, as the flanking force may itself be ambushed while maneuvering, or the main force is unable to pin the defenders in place, allowing them to turn and face the flanking attack. During the second Persian invasion of Greece, after great losses at the Battle of Thermopylae and the Battle of Artemisium, the Greeks once again brought the Persians to blows in the Battle of Salamis in the year 480 BC. The Greek fleet numbered 378 triremes while the Persian may have numbered more than four times that. However, in the narrow confines of the straits, the numerical superiority of the Persians became an active hindrance. The Persians became disorganized in the cramped straits, and the Greeks were in a position to flank from the northwest. Retreating Persian ships were befouled by the approaching second and third lines who were advancing to the line of battle. In the aftermath of the battle, Xerxes retreated to Asia with the majority of his army. In his wake he left Mardonius, who would be decisively defeated by the Greek army the following year in the Battle of Plataea. In 371 BC, the armies of Sparta and Thebes gave battle near the city of Leuctra, despite the superior numbers and fearful reputation of the Spartan army, the unbalanced Theban attack, with the Sacred Band of Thebes on the extreme left and in echelon formation disorganized the Spartan lines and spread confusion in its army. Before even the extreme Spartan right wing had entered the fray, the battle was lost for them. It was Epaminondas greatest triumph and shattered the myth of Spartan invincibility.