At Leuctra (371 B.C.) and again at Mantinea (362 B.C.) the right wing of the Lacedaemonian Army, composed exclusively of Spartans and for six hundred years invincible, was overthrown and destroyed by the Sacred Band led by Epaminondas. This formidable body of Theban warriors was massacred by Alexander the Great at the Battle of Chaeronea (338 B.C.) * * * * * The _Macedonian Phalanx_ was devised by Philip, King of Macedon. It was made up of heavy infantry accoutred with cuirass, helmet, greaves, and shield. The principal weapon was a pike twenty-four feet long. The Phalanx had a front of two hundred and fifty-six files and a depth of sixteen ranks. A file of sixteen men was termed Lochos; two files were called Dilochie; four files made a Tetrarchie; eight files a Taxiarchie and thirty-two of the last constituted a simple Phalanx of 4096 men. A grand Phalanx had a front of one thousand and twenty-four files and a depth of sixteen ranks. It was made up of four simple Phalanxes and contained 16,384 men. With this formation of his infantry, Alexander the Great, when eighteen years of age, destroyed the Allied Athenian--Theban--Boeotian army at Chaeronea, the hosts of Persia at the river Grancius (334 B.C.) at Issus (333 B.C.) and Arbela (331 B.C.) and conquered Porus, King of India at the Hydaspes (326 B.C.). * * * * * The _Spanish Heavy Cavalry_ and _Nubian Infantry_ of Hannibal was a reproduction of that Macedonian organization whereby Alexander the Great had conquered the world. With this formation Hannibal maintained himself for fifteen years in the richest provinces of Italy and destroyed seven Roman armies, at the Trebia (218 B.C.) at Lake Trasymenus (217 B.C.) at Cannae (216 B.C.) and at Herdonea (212 B.C.) at Herdonea (210 B.C.) at Locri (208 B.C.) and at Apulia (208 B.C.). At Zama (202 B.C.) Hannibal’s effacement as a military factor was directly due to his lack of that organization which had been the instrument of his previous successes; a circumstance thus commented on by the victorious Roman commander, Scipio Africanus; “Hitherto I have been opposed by an army without a general; now they send against me a General without an army.” * * * * * The _Tenth Legion_ of Caesar was the quintessence of that perfection in elementary tactics devised by the Romans to accord with the use of artillery. The fundamentals of minor tactics as elucidated by Epaminondas and exploited by Alexander the Great and Hannibal are unchanged in the Legion, but by subdivision of the simple Phalanx into ten Cohorts, a necessary and maximum gain in mobility was effected.