News of the Illyrian revolt under Cleitus the Dardanian, and King Glaukias of the Taulanti first reached the ears of Alexander while he was campaigning on the Danube against some of the northern tribes that his father, Philip II of Macedon had previously reduced to a satisfactory level of subjection, although not outright submission. As this area had been far from the Greek theatre of operations, Phillip had been satisfied with the level of subjection he had reduced them to.