Companion Cavalry
                        The cavalry Companions were heavily armored horsemen who were armed with a spear and sword.  In Alexanders campaignes there were 200-300 units of these horsemen and their were a handful of Royal Companions that were called agema.  These units were a key factor in this war especially because they were a swift way of getting place to place, and also quick in battle despite the fact the men riding were armored.
       
        Hypaspists
                       The Hypaspists were very effective in Alexanders battles because of their wide range of tactics.  They could almost complete any task even though they were infantry.  They acted as an aid to the phalanx by protecting the right flank and they were also good for skirmishing, and storming walls.  They were even quick enough to aid the cavalry.

        Phalanx/Hoplites
                       The Greek hoplites are very different from the Macedonian hoplites.  The Greek hoplites has an enourmous shield which was quite heavy only enabling them to carry a small pike or spear because the weight in both arms would be too much to bear.  Knowing this King Philip made the shields of the hoplites smaller and now instead of being held the shields were slung over their left shoulders enableing them to carry a spear anywhere from 13-17 ft  in both hands.  Another adjustment Philip made was that he lengthened the phalanx to 16 rows of men instead of the Greek phalanx which had 8.  The first five rows of men in the Macedoinian phalnx had their sarisa or spears pointing forward.  The rest of the rows had their sarisa pointing to the sky.  This provided a good defense against the enemy missiles.

           Auxilary Troops

                        Alexander did not only bring his own men on his campaigns but he also employed many auxilary, or allied troops, and brought them too.  Probably the most effective auxilary troops were the Thessalians, these people had the best horses and they were the best horsemen.  The elite group of the Thessalian horsemen were called the Pharsalus Squadron, these men were the people who protected the ruler of Thessaly.

                   Macedonian Seigecraft

                                The oxybeles was the most common form of seige craft that the King Philip had established.  They had a missile engine that would hurl darts or large bolts at the enemy forces, ranging up to a quarter mile.   Alexander's battle with the Scythians was the first place in his campaighns where the use of artillery was used. His train included siege ladders, battering-rams and siege towers, and many of his engines were built on the spot. Alexander's chief engineer was Diades, and as u can see he must have been a large part in getting to Alexanders goal.  
                       
          Some probable army sizes

            Macedonian invasion force of 334 BC - 36,000
            Macedonians at Issus - 30,000
            Macedonians at Gaugamela - 47,000
            Macedonians at the Hydaspes - 41,000
            Persians at the Granicus - 25,000
            Persians at Issus - 100,000
            Persians at Gaugamela - 90,000
            Indians at the Hydaspes - 30,000

            agema - élite units of the hetairoi and hypaspists
            argyraspids - Silver Shields; Macedonian veteran crack infantry; 3,000 strong
            hetairoi - Macedonian Companion cavalry; heavily armored nobilty horsemen
            hipparchy - four ilai of hetairoi
            hoplite - heavily armored Greek footman
            hoplon - large round shield of the Greek hoplites; wooden core covered with bronze
            hypaspists - Macedonian crack infantry; 3,000 strong
            ile (plural: ilai) - squadron of hetairoi; 200-300 horsemen
            javelin - 4 feet or 5 feet long spear; missile weapon
            pelta - wicker shield of the peltasts
            peltast - lightly-armed infantry man armed with a bundle of javelins and a wicker shield; Thracian origin
            pezhetairoi - Foot Companions of the Macedonian phalanx; infantry carrying the sarisa and a light shield
            phalanx - Greece: battle line formation of hoplites, usually 4 to 8 deep; Macedonia: battle line formation of pezhetairoi, usually 16 deep and divided in                                     taxis
            prodromoi - Thracian light cavalry; mounted scouts armed with a sarisa
            sarisa - 13 feet to 17 feet pike used by the Macedonian pezhetairoi (phalanx)
            sarisophori - prodromoi
            taxis - Macedonian phalanx battalion of 1,526 pezhetairoi
            xyston - short thrusting spear or lance of the hetairoi and Thessalian cavalry

                               

            Battles (Major)

                           Battle of Granicus - 334 B.C.
                           Battle of Issus - 333 B.C.
                           Battle of  Gaugamela - 331 B.C.
                           Battle of Hydaspes - 326 B.C.