Wars of Alexander the Great participant Illyrians
Balkan campaign
Before crossing to Asia, Alexander wanted to safeguard his northern borders and, in the spring of 335 BC, he advanced into Thrace to deal with the revolt, which was led by the Illyrians and Triballi. At Mount Haemus, the Macedonian army attacked and defeated a Thracian garrison manning the heights. The Macedonians were then attacked in the rear by the Triballi, who were crushed in turn. Alexander then advanced on to the Danube, encountering the Getae tribe on the opposite shore. The Getae army retreated after the first cavalry skirmish, leaving their town to the Macedonian army. News then reached Alexander that Cleitus, King of Illyria, and King Glaukias of the Taulantii were in open revolt against Macedonian authority. Alexander defeated each in turn, forcing Cleitus and Glaukias to flee with their armies, leaving Alexander's northern frontier secure.While he was triumphantly campaigning north, the Thebans and Athenians rebelled once more. Alexander reacted immediately, but, while the other cities once again hesitated, Thebes decided to resist with the utmost vigor. This resistance was useless, however, as the city was razed to the ground amid great bloodshed and its territory divided between the other Boeotian cities. The end of Thebes cowed Athens into submission, leaving all of Greece at least outwardly at peace with Alexander.