The League was created in order to unify Greek military forces under Macedonian leadership (hegemony) in their combined conquest of the Persian Achaemenid Empire.
Alexander utilized his father's league when planning his pan-Hellenic invasion of Asia to expand Macedon and take revenge on the Persian Empire.
[12][13][14] The organization was the first time in history that the Greek city-states (with the notable exception of Sparta, which would join only later under Alexander's terms) would unify under a single political entity.
[9] Following his victory at the Battle of Chaeronea (337 BC), Philip was able to impose a settlement upon southern Greece, which all states accepted, with the exception of Sparta.
[17] In mid 337 BC, he seems to have camped near Corinth and began the work to establish a league of the city-states, which would guarantee peace in Greece and provide Philip with military assistance against Persia.
[30] (A fragmentary inscription of the oath was found in Athens)[31][32] [․․․․․․․․․21․․․․․․․․․․ Ποσ]ειδῶ ․․5․․ ․․․․․․․․․․22․․․․․․․․․․ς ἐμμεν[ῶ ․․․․] ․․․․․․․․․․22․․․․․․․․․․νον[τ]ας τ․․․․ [․․․․․․․․18․․․․․․․․ οὐδ]ὲ ὅπλα ἐ[π]οί[σω ἐ]- [πὶ πημονῆι ἐπ’ οὐδένα τῶν] ἐμμενόντ[ω]ν ἐν τ- [οῖς ὅρκοις οὔτε κατὰ γῆν] οὔτε κατὰ [θ]άλασ- [σαν· οὐδὲ πόλιν οὐδὲ φρο]ύριον καταλήψομ- [αι οὔτε λιμένα ἐπὶ πολέ]μωι οὐθενὸς τῶν τ- [ῆς εἰρήνης κοινωνούντ]ων τέχνηι οὐδεμι- [ᾶι οὔτε μηχανῆι· οὐδὲ τ]ὴν βασιλείαν [τ]ὴν Φ- [ιλίππου καὶ τῶν ἐκγόν]ων καταλύσω ὀδὲ τὰ- [ς πολιτείας τὰς οὔσας] παρ’ ἑκάστοις ὅτε τ- [οὺς ὅρκους τοὺς περὶ τ]ῆς εἰρήνης ὤμνυον· [οὐδὲ ποιήσω οὐδὲν ἐνα]ντίον ταῖσδε ταῖς [σπονδαῖς οὔτ’ ἐγὼ οὔτ’ ἄλ]λωι ἐπιτρέψω εἰς [δύναμιν, ἀλλ’ ἐάν τις ποε̑ι τι] παράσπονδ[ον] πε- [ρὶ τὰς συνθήκας, βοηθήσω] καθότι ἂν παραγ- [γέλλωσιν οἱ ἀεὶ δεόμενοι] καὶ πολεμήσω τῶ- [ι τὴν κοινὴν εἰρήνην παρ]αβαίνοντι καθότι [ἂν ἦι συντεταγμένον ἐμαυ]τῶι καὶ ὁ ἡγε[μὼ]- [ν κελεύηι ․․․․․12․․․․․ κα]ταλείψω τε․․ — — — — — — — — — — — — — :𐅃 [— — — — — — — — — — : Θεσ]σαλῶν :Δ [— — — — — — — — — — — ῶ]ν :ΙΙ [— — — — — — — — — Ἐλειμ]ιωτῶν :Ι [— — — — Σαμοθράικων καὶ] Θασίων :ΙΙ — — — — — — — — — ων :ΙΙ: Ἀμβρακιωτ[ῶν] [— — — — — — — ἀ]πὸ Θράικης καὶ [— — — — — :] Φωκέων :ΙΙΙ: Λοκρῶν :ΙΙΙ [— — — — Οἰτ]αίων καὶ Μαλιέων καὶ [Αἰνιάνων :ΙΙΙ: — καὶ Ἀγ]ραίων καὶ Δολόπων :𐅃 [— — — — — — : Πε]ρραιβῶν :ΙΙ
Alexander, son of Philip, and the Hellenes, except the Lacedaemonians, from the barbarians inhabiting Asia[36]Also, Diodorus Siculus (Βίβλος ΙΖ’ 48.
[6]) mentions the council's decision in 333 BC, after the Battle of Issus, to send ambassadors to Alexander that will bring the Excellence of Greece (Golden Wreath).
[38] During the Asiatic campaign, Antipater was appointed deputy hegemon of the League[39] while Alexander personally recommended that the Athenians turn their attention to things; in case something happened to him, Athens would take over the power in Greece.
[41] Following the victory of Demetrius I Poliorcetes at the Battle of Salamis in 306 BC, his father, Antigonus I Monophthalmus, assumed the title of Basileus ("King" of Alexander's Empire) by the assembled armies and gained control over the Aegean, the eastern Mediterranean, and most of the Middle East.