Phillip II was a King of Macedon best known for being the father of Alexander the Great. The greatest achievements conquered by his son would not be possible without the reformation he introduced in the army.
He creates a full-time military service to improve the troops and develop the phalanx technic that was crucial for the victories on the battlefield.
They protected early civilization from most invaders, is the correct answer. The Himalayas have been shielding India from outside invaders since the early occasions.
