Final answer:
Alexander the Great won all three thrusts at the beginning of the war, quickly subjugating rebellions and leading Macedonian forces to victories over Persian King Darius III at Issus and Gaugamela.
Step-by-step explanation:
The individual who won all three thrusts at the beginning of the war was Alexander the Great. He inherited his father Philip II's throne and immediately faced threats from Thracian tribes and rebellions within Greece itself. Despite these initial challenges, Alexander swiftly dealt with these domestic issues before executing his father's plan to confront the Persian Empire. Under Alexander's leadership, the Macedonian forces defeated King Darius III's armies at significant battles such as Issus in 333 BCE and Gaugamela in 330 BCE. These victories demonstrated Alexander's military genius and positioned him as a conqueror of the Persian Empire, further cementing his legacy as one of history's most renowned military commanders and strategists.