The wars of Alexander the Great were a series of wars, fought over a span of thirteen years (from 336-323 BC), that were carried out by King Alexander III of Macedon (his moniker being Alexander “The Great”). The wars began with the battles against the Achaemenid Persian Empire under the rule of former King Darius III. After Alexander’s chain of victories against Persia, he then began to skirmish with local chieftains and warlords stretching as far as modern-day Punjab, India. By the time of his death, he was emperor over most regions of Greek culture and the conquered Persian Empire (including much of Egypt). He did not manage to conquer all of South Asia as was his initial plan. Although he was a very successful military commander, he did not provide any stable alternative to the Achaemenid Empire, and his untimely death threw the vast territories he conquered into civil war.
Alexander assumed the kingship of Macedonia following the assassination of his father King Philip II. Philip, during his rule, had unified most of the city-states of mainland Greece (of Macedonian hegemony) under a federation called the Hellenic League (also known as the League of Corinth). Alexander proceeded to solidify Macedonian rule by quashing a rebellion that took place in the southern Greek city-states, and also staged a short but bloody excursion against the states to the north. He then proceeded east in order to carry out his plans to conquer the Achaemenid Persian Empire, which was then ruled by Darius III. His conquests included Anatolia, Syria, Phoenicia, Judea, Gaza, Egypt, Mesopotamia, Persia and Bactria. He extended the boundaries of his empire as far as Taxila, India (now Pakistan).
Alexander had initially made plans, prior to his death, for military and mercantile expansion into the Arabian Peninsula, after of which he planned to turn his armies to the west (Carthage, Rome, and the Iberian Peninsula). However, Alexander’s diadochi (being his rival generals, families, and friends) quietly abandoned these plans after he died. Instead, within a few years of Alexander’s death, the diadochi began fighting with each other and divided up the Empire between themselves, triggering 40 years of warfare.