From various sources online. Most of these do not necessarily apply to this topic: "Origin of Macedonian Kings".
Strabo, Geography
Book VII, Chapter 7
"And even to the present day the Thracians, Illyrians, and Epirotes live on the flanks of the Greeks; indeed most of the country that at the present time is indisputably Greece is held by barbarians - Macedonia and certain parts of Thessaly by the Thracians, and the parts above Acarnania and Aetolia by the Thesproti, the Cassopaei, the Amphilochi, the Molossi, and the Athamanes - Epirotic tribes."
Note the clear statement that Macedonia is held by the Thracians; that is, Thracians formed the ethnic majority in Macedonia. Thracians also held "certain parts of Thessaly".
Alexander's mother Olympias was a Molossian.
Titus Livius, 'Rome and the Mediterranean'
Book XXXI, page 23, Penguin Classics edition: "...and yet it had a claim to fame almost greater, because of the ancient renown of the Macedonian nation, and the vast extent of their empire, which gave them possession, by conquest, of large tracts of Europe, and the greater part of Asia."
Book XXXII (XXXII.23, pg. 93): "...there was no doubt in their minds that they would easily dislodge the Macedonians and the Greeks."
Book XXXII.34, pg. 101: "Phaeneas, chief magistrate of the Aetolians, made substantially the same demands as the Romans: the withdrawal of the Macedonians from Greece."
Book XXXII.34, pg. 101: "Then he (Philip) began to complain that the Aetolians, like the Romans, were telling him to withdraw from Greece, although they were unable to tell him what were the boundaries of Greece."
As a king of Greek ethnic origin, Philip should be well aware of the boundaries of Greece.
Book XXXVI.17, pg. 253: "There, as you well know, they were Macedonians, Thracians, and Illyrians - all very warlike races: here you have Syrians and Asiatic Greeks, the most worthless types of men, born for slavery."
Others, various authors:
"Such were the activities of the Romans and of Philip on land during that summer. At the beginning of the same summer, the fleet, commanded by the legate Lucius Apustius, left Corcyra, rounded Cape Malea, and joined King Attalus of Scyllaeum, in the region of Hermoine. Hitherto the resentment of the Athenian community against Philip had been kept in check by fear; but now, with the hope of assistance ready at hand, they gave free rein to their anger. There is never any lack at Athenian tongues ready and willing to stir up the passion of the common people; this kind of oratory is nurtured by the applause of the mob in all free communities; but this is especially true of Athens, where eloquence has the greatest influence. The popular assembly immediately carried a proposal that all statues of Philip and all portraits of him, with their inscriptions, and also those of his ancestors of either sex, should be removed and destroyed; that all feast-days, rites, and priesthoods instituted in honour of Philip or his ancestors should be deprived of sanctity; that even the sites of any memorials or inscriptions in his honour should be held accursed, and that it should not be lawful thereafter to decide to set up or dedicate on those sites any of those things which might lawfully be set up or dedicated on an undefiled site; that whenever the priests of the people offered prayer on behalf of the Athenian people and their allies, their armies and navies, they should on every occasion HEAP CURSES and execrations on Philip, his family and his realm, his forces on land and sea, AND THE WHOLE RACE AND NAME OF THE MACEDONIANS."
Pausanias
"Leosthenes at the head of the Athenians and the united Greeks defeated the Macedonians in Boeotia and again outside Thermopylae forced them into Lamia" [1.1.3].
"I have already said in my history of Attica that the defeat at Chaeronea was a disaster for all the Greeks" [9.6.5].
"After the death of Alexander, when the Greeks had raised a second war against the Macedonians, the Messenians took part, as I have shown earlier in my account of Attica" [4.28.3].
"When Philip the son of Amyntas would not let Greece alone, the Eleans, weakened by civil strife, joined the Macedonian alliance, but they could not bring themselves to fight against the Greeks at Chaeronea. They joined Philip's attack on the Lacedaemonians because of their old hatred of that people, but on the death of Alexander they fought on the side of the Greeks against Antipater and the Macedonians" [5.4.9].
"When Philip, the son of Demetrius, reached men's estate, and Antigonus without reluctance handed over the sovereignty of the Macedonians, he struck fear into the hearts of all the Greeks. He copied Philip, the son of Amyntas" [7.7.5].
Thrasymachus
"Shall we being Greeks, be slaves to Archelaus, a barbarian?"
This line the Greek Thrasymachus attributed to the Macedonian king Archelaus who occupied Greek land with his Macedonian army.
Strabo, Geography
Book VII, Chapter 7
"And even to the present day the Thracians, Illyrians, and Epirotes live on the flanks of the Greeks; indeed most of the country that at the present time is indisputably Greece is held by barbarians - Macedonia and certain parts of Thessaly by the Thracians, and the parts above Acarnania and Aetolia by the Thesproti, the Cassopaei, the Amphilochi, the Molossi, and the Athamanes - Epirotic tribes."
Note the clear statement that Macedonia is held by the Thracians; that is, Thracians formed the ethnic majority in Macedonia. Thracians also held "certain parts of Thessaly".
Alexander's mother Olympias was a Molossian.
Titus Livius, 'Rome and the Mediterranean'
Book XXXI, page 23, Penguin Classics edition: "...and yet it had a claim to fame almost greater, because of the ancient renown of the Macedonian nation, and the vast extent of their empire, which gave them possession, by conquest, of large tracts of Europe, and the greater part of Asia."
Book XXXII (XXXII.23, pg. 93): "...there was no doubt in their minds that they would easily dislodge the Macedonians and the Greeks."
Book XXXII.34, pg. 101: "Phaeneas, chief magistrate of the Aetolians, made substantially the same demands as the Romans: the withdrawal of the Macedonians from Greece."
Book XXXII.34, pg. 101: "Then he (Philip) began to complain that the Aetolians, like the Romans, were telling him to withdraw from Greece, although they were unable to tell him what were the boundaries of Greece."
As a king of Greek ethnic origin, Philip should be well aware of the boundaries of Greece.

Book XXXVI.17, pg. 253: "There, as you well know, they were Macedonians, Thracians, and Illyrians - all very warlike races: here you have Syrians and Asiatic Greeks, the most worthless types of men, born for slavery."
Others, various authors:
"Such were the activities of the Romans and of Philip on land during that summer. At the beginning of the same summer, the fleet, commanded by the legate Lucius Apustius, left Corcyra, rounded Cape Malea, and joined King Attalus of Scyllaeum, in the region of Hermoine. Hitherto the resentment of the Athenian community against Philip had been kept in check by fear; but now, with the hope of assistance ready at hand, they gave free rein to their anger. There is never any lack at Athenian tongues ready and willing to stir up the passion of the common people; this kind of oratory is nurtured by the applause of the mob in all free communities; but this is especially true of Athens, where eloquence has the greatest influence. The popular assembly immediately carried a proposal that all statues of Philip and all portraits of him, with their inscriptions, and also those of his ancestors of either sex, should be removed and destroyed; that all feast-days, rites, and priesthoods instituted in honour of Philip or his ancestors should be deprived of sanctity; that even the sites of any memorials or inscriptions in his honour should be held accursed, and that it should not be lawful thereafter to decide to set up or dedicate on those sites any of those things which might lawfully be set up or dedicated on an undefiled site; that whenever the priests of the people offered prayer on behalf of the Athenian people and their allies, their armies and navies, they should on every occasion HEAP CURSES and execrations on Philip, his family and his realm, his forces on land and sea, AND THE WHOLE RACE AND NAME OF THE MACEDONIANS."
Pausanias
"Leosthenes at the head of the Athenians and the united Greeks defeated the Macedonians in Boeotia and again outside Thermopylae forced them into Lamia" [1.1.3].
"I have already said in my history of Attica that the defeat at Chaeronea was a disaster for all the Greeks" [9.6.5].
"After the death of Alexander, when the Greeks had raised a second war against the Macedonians, the Messenians took part, as I have shown earlier in my account of Attica" [4.28.3].
"When Philip the son of Amyntas would not let Greece alone, the Eleans, weakened by civil strife, joined the Macedonian alliance, but they could not bring themselves to fight against the Greeks at Chaeronea. They joined Philip's attack on the Lacedaemonians because of their old hatred of that people, but on the death of Alexander they fought on the side of the Greeks against Antipater and the Macedonians" [5.4.9].
"When Philip, the son of Demetrius, reached men's estate, and Antigonus without reluctance handed over the sovereignty of the Macedonians, he struck fear into the hearts of all the Greeks. He copied Philip, the son of Amyntas" [7.7.5].
Thrasymachus
"Shall we being Greeks, be slaves to Archelaus, a barbarian?"
This line the Greek Thrasymachus attributed to the Macedonian king Archelaus who occupied Greek land with his Macedonian army.
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