Alexander II of Macedon (r.369-368/7 BC) was a short-lived monarch, who was murdered by Ptolemy Alorites, probably his brother in law.
Alexander was the eldest son of Amyntas III and Eurydice. Amyntas was one of the few kings of Macedon to enjoy a long reign that ended with a natural death. After his father's death in 369 BC Alexander inherited the throne.
At the start of his reign Alexander intervened in Thessaly, where Alexander, tyrant of Pherae, had seized power and made himself increasingly unpopular with his misrule. A group of rebels from Larissa came to Macedon and convinced Alexander to support them. Alexander of Pherae discovered that Alexander II was preparing to intervene, raised an army of his own, and moved north to invade Macedon. Alexander II and the exiles moved first and were secretly admitted into Larissa. Alexander II then besieged the citadel, which fell to him, and also captured Crannon. At first he agreed to return these cities to Thessalian control, but he then decided to keep them for himself. Alexander of Pherae managed to escape back to Pherae.
This may have triggered the first of Pelopidas of Thebe's first intervention in Macedon. He had also been called into Thessaly to overthrow Alexander of Pherae, but when he reached Larissa he found the citadel in the hands of Alexander of Macedon. The Macedonians surrendered control of the citadel to Pelopidas, who then moved north into Macedon, where he agreed an alliance with Alexander II. According to Diodorus this is when Alexander's youngest brother, the future Philip II, was sent to Thebes as a hostage. According to Plutarch Pelopidas moved north to intervene in a civil war between Alexander II and his probable brother-in-law Ptolemy Alorites. It is possible that Ptolemy was taking advantage of Alexander's absence in Thessaly, although Macedonian history in this period was full of similar revolts.
Alexander was murdered in 368/7, probably by Ptolemy Alorites. Justin records a plot involving Alexander's mother Eurydice, who first planned to murder her husband Amyntas II acting with her unnamed son-in-law. This son-in-law was probably Ptolemy, who was described as the brother-in-law of Alexander and Perdiccas III. Justin then has Alexander murdered as a result of a plot led by Eurydice, although this doesn’t exclude Ptolemy's participation. However Justin also states that Perdiccas was also killed as a result of one of Eurydice's plots, when he was actually killed in battle against the Illyrians.
Alexander's death probably triggered two foreign interventions in Macedon. His younger brother probably succeeded him as Perdiccas III, with Ptolemy Alorites as regent. The new regime was threatened by a rebellion led by Pausanias, a member of a rival branch of the royal family, but this revolt was defeated by the Athenian commander Iphicrates. The second intervention involved the Theban commander Pelopidas, who led a force of mercenaries north into Macedon to punish Ptolemy. Ptolemy managed to bribe the mercenaries, but still decided to submit to Pelopidas, not wanting to risk a clash with Thebes.