![\"alexanders-army\"](\"https:\/\/www.in2greece.com\/english\/historymyth\/history\/ancient\/wp-content\/uploads\/2026\/06\/alexander-1s-army-1-300x187.jpg\")
Alexander’s army in front of the walls of Thebes numbered more than 30,000 infantry and 3,000 cavalry, that is, almost the entire force with which he attacked Persia.<\/p>\nThe strength of Alexander’s army is one of the many elements for which there is incomplete information. Not even for the initial force, which started from Macedonia, there is no accurate information and the only thing certain is that Alexander conducted the European campaign at the head of the forces of the Joint Congress of the Greeks. This is clear because:<\/p>\n
Philip was assassinated a few months before attacking Persia, so the allied forces must have already gathered and made the final preparations.<\/p>\n
Alexander’s army in front of the walls of Thebes numbered more than 30,000 infantry and 3,000 cavalry, that is, almost the entire force with which he attacked Persia.<\/p>\n
The complete destruction of Thebes was decided by Alexander’s Greek allies. In the few months that intervened between the destruction of Thebes and the invasion of Asia, that is, in the winter of 335334 BC, it is neither mentioned nor was it possible to gather all the allied forces and the supplies necessary for the campaign<\/p>\n
It is also certain that the Thracian peoples offered an army to Alexander after his campaign against them and their complete submission.<\/p>\n
The total strength of the initial army is one of the many points of disagreement of the ancient authors, who deliver from 30,000 to 43,000 infantry and from 4,000 to 5,500 cavalry.
Arrian, who is the most detailed historian in describing the battles, gives us only approximate totals, because probably none of his sources satisfied him. On the contrary, Diodorus, who is more concise and less reliable, gives us the only, somewhat detailed list of the initial strength of Alexander’s army. However, in no case should we attribute any special value to this list for the following reasons:<\/p>\n
Arrian, in the battle of the Granicus, in the crossing of Cilicia and in the battle of Issus, mentions units that do not appear to have joined the army during its advance, and therefore belonged to its initial strength, but are not included in Diodorus’ list. But Diodorus himself limits the value of his list.<\/p>\n
Specifically, he does not specify the specialty of the Balkan peoples (Odrysians, Triballians and Illyrians) that he mentions. He also mentions the Paeonian people of the Agrianes as archers, while Arrian states that they were javelin throwers. However, both seem to agree that the Agrianes numbered about 1,000. Elsewhere, he informs us that the 600 horsemen from the allied states of southern Greece included Peloponnesians and Achaeans, giving the impression that Achaia is not located in the Peloponnese. The truth is that these do not constitute serious offenses, because all ancient writers used similar formulations. The most important problem is that he lists 5,100 horsemen, but sums them up to 4,500!<\/p>\n
The initial army with which Alexander attacked the Achaemenid Empire was about \u00be of the total military force that had been assembled. The remaining \u00bc, 12,000 infantry and 1,500 cavalry, remained on European soil under Antipater, to maintain the Macedonian Hegemony in Greece and the subjugation of the Thracian peoples. To this force we must add the 10,000 Macedonians, who had been operating in Asia Minor for a year already, although we have no information about their actions after the assassination of Philip. After each victory and as the army advanced in Asia, other forces from the local troops of the subjugated countries joined. Thus, during the invasion of India and despite the garrisons it had left behind throughout Asia, the army is reported to have numbered 120,000 combatants.<\/p>\n
The nature of the military conflict, prepared by Philip and carried out by Alexander, required the mobilization of large military formations and large-scale battles. Despite this, there was no shortage of unorthodox tactics, traditionally used by Greek armies, to win with the least possible losses in time, personnel and resources. The most characteristic examples per category are the following.<\/p>\n
In Myndos, Alexander came to an agreement with a portion of the inhabitants, who preferred surrender, but were ultimately neutralized by those who preferred resistance. As a top case of an agreement we must consider the retention in their positions of officials of the Persian state, who surrendered. Although not directly recorded by ancient sources, all relevant cases must be considered as the result of a previous agreement, because such agreements were mutually beneficial and ensured Alexander a great speed of advance and additional resources, and the officials involved privileges similar to, or the same as, those they already possessed.<\/p>\n
Only two night operations are recorded and they are defensive, the first in Halicarnassus and the second in the country of the Aspasians. The reason why Alexander did not choose them is that they are successfully carried out by small forces against large ones, while his own forces were already large and would have faced difficulty in coordinating them. At Gaugamela, for this very reason, he rejected the proposal for a night attack and this is probably the reason why the extensive Persian front collapsed.<\/p>\n
In Sogdiani Petra, the only real and technically impressive expeditionary operation is recorded, which was however designed to bring about a psychological rather than a tactical effect. In Hydaspes, the use of misleading information and actions is recorded. Alexander spread the word that he did not intend to cross the river before its level fell and at night he unnecessarily moved various divisions in order to convince Porus of his disseminated intentions. Finally, he managed to surprise Porus and land his forces on the eastern bank of the Hydaspes, without being noticed in time. Due to the concealment of the watercraft and the weather conditions under which the landing took place, we can also consider it as an expeditionary operation.<\/p>\n
One last observation is that in all conflicts Alexander avoided using the subjugated barbarians of Asia as a striking force, that is, he did not make the mistake that Darius made in the battle of Issus with the Kardaccas (Kurds). He always used the initial part of the army, which started from Greece, and only in specific cases did he use specialized units of Asians, such as the horse archers.<\/p>","protected":false},"excerpt":{"rendered":"