Pausanias Description of Greece 1.9.5

[5]
  This Lysimachus was a Macedonian by birth and one of Alexander's body-guards, whom Alexander once in anger shut up in a chamber with a lion, and afterwards found that he had overpowered the brute. Henceforth he always treated him with respect, and honored him as much as the noblest Macedonians. After the death of Alexander, Lysimachus ruled such of the Thracians, who are neighbors of the Macedonians, as had been under the sway of Alexander and before him of Philip. These would comprise but a small part of Thrace . If race be compared with race no nation of men except the Celts are more numerous than the Thracians taken all together, and for this reason no one before the Romans reduced the whole Thracian population. But the Romans have subdued all Thrace , and they also hold such Celtic territory as is worth possessing, but they have intentionally overlooked the parts that they consider useless through excessive cold or barrenness.

[5] This Lysimakhos was a Macedonian by birth and one of Alexander’s bodyguards [ doruphoroi], whom Alexander once in anger shut up in a chamber with a lion, and afterwards found that he had overpowered the beast. Henceforth he always treated him with respect, and honored him as much as the noblest Macedonians. After the death of Alexander, Lysimakhos ruled those of the Thracians, who are neighbors of the Macedonians, who had been under the sway of Alexander and before him of Philip. These would comprise but a small part of Thrace. If populations be compared with populations no people except the Celts are more numerous than the Thracians taken all together, and for this reason no one before the Romans reduced the whole Thracian population. But the Romans have subdued all Thrace, and they also hold such Celtic territory as is worth possessing, but they have intentionally overlooked the parts that they consider useless through excessive cold or barrenness.