Alexander the Great (366-323 BC) was the son of King Philip of Macedon (to the north of Greece) and his wife Olympias.
Philip II (382-336 B.C.) of Macedon gathered a large force of infantry and cavalry and set out to challenge the Persians. He had married Olympias, daughter of the King of Epirus, but according to Plutarch, soon after his marriage, Philip found Olympias asleep with a serpent beside her, and began to fear and hate her as an enchantress.

Macedonians were regarded as hillbillies by the Greeks of Athens. Alexander's father was sore about this, and hired the philosopher Aristotle as a teacher for young Alexander, so Alexander grew up speaking Attic Greek, and with a respect for Greek traditions. He carried a copy of Homer's Illiad everywhere with him, and always slept with it under his pillow beside his dagger.

Alexander's faithful companion in both battle and the hunt was his horse Bucephalus ("Ox-head"). Plutarch (6.1-4) records that when he was barely fifteen, Alexander tamed this tempestuous and unruly steed. Bucephalus had been brought to Philip by a Thessalian who demanded the exorbitant sum of thirteen talents for the horse. When an attendant attempted to mount him, the horse reared up and threw him to the ground. As the horse was being led away, Alexander exclaimed that he was able to mount him. Philip mocked his son and asked him what sum he would pay if he were unhorsed. Alexander replied that he would pay his father the full price of the horse. The king and his attendants burst out into loud laughter, but Alexander ran to the horse and turned him directly towards the sun. Alexander had noticed that Bucephalus was spooked by the motion of his own shadow. He then led the horse forward, stroking him gently, mounted him, let him go at full gallop. According to Plutarch (6.5), when Alexander dismounted, Philip embraced him and said. "O my son, look thee out a kingdom equal to and worthy of thyself, for Macedonia is too small for thee."

As a result of his estrangement from Alexander's mother, Philip married several other women. One of them was a younger girl, named Cleopatra. At the wedding feast Attalus, the bride's uncle, became drunk and implored the gods to give the couple a lawful heir to the kingdom. Alexander was outraged by this insult and threw his drinking cup at Attalus' head. Philip rose in anger with his sword drawn to attack his son, but his foot slipped and he fell to the ground. Plutarch (9.4-5) records that Alexander exclaimed, "See there, the man who makes preparations to pass out of Europe into Asia, overturned in passing from one seat to another."

Alexander and Olympias withdrew from the royal court. Olympias returned to Epirus, and Alexander traveled to Illyria.

After subjugating his neighbors, Philip invaded mainland Greece. In 337 BC he called a congress of the Greek states in the Peloponnese. A Hellenic league was organized which acknowledged Philip as the military commander and furnished contingents for an expedition against Persia.
In 336 Philip was murdered during the marriage festivities of his daughter in Aegae, Macedon. He left behind him a kingdom beset by troubles, but he also left the Macedonian army that enabled his son within ten years to change the face of the known world.
Alexander was barely twenty years old when Philip was murdered. The countries surrounding Macedonia wanted to free themselves of its rule. The Greek cities were on the verge of rebellion. Alexander acted with speed to put down the revolts and at the general assembly at the Isthmus or the Peloponnese the Greek cities agreed to join him in the war against Persia, and proclaimed him their general.

Public officials and philosophers came from all parts of the land to congratulate Alexander - all but Diogenes of Sinope who was living at the time in Corinth. According to Plutarch (14.1-2), Diogenes did not even bother to leave Cranium, the suburb where Alexander found him lying in the sun. When the philosopher saw so much company about him, he raised himself a little and glanced at Alexander who asked him kindly whether he wanted anything. Diogenes replied, "Yes, I would have you move from between me and the sun." Alexander was struck by this answer and was so impressed by the man that he told his followers that, were he not Alexander, he would choose to be Diogenes.

Alexander's aim was to strike at the heart of the Persian empire and ultimately to conquer the entire East. He crossed the Hellespont into Asia and made a detour to Troy, where he sacrificed to Athena, and honored the memories of the heroes buried there.

The Persian advance guard was encamped on the further bank of the Granicus river. Except for a few hand-picked soldiers and a body of Greek mercenaries, the Persian king depended upon oriental recruits, large in number but weak in fighting power
Alexander crossed the river on horseback and was met by a shower of arrows. He charged, horse against horse with his raised lance. While the horsemen were engaged, the Macedonian phalanx crossed the river. The Persians took fright and fled, leaving the high roads of Asia Minor open to the Macedonians.
News of the disaster reached Darius, who marched at the head of a large force towards Cilicia to engage Alexander in battle. The armies met at Issus (near modern Alexandretta) in October, 333 BC. Alexander fought in the foremost ranks while his army closed in on the Persians and put them to flight. Darius escaped and fled, leaving behind his queen, his mother, and his daughters to be captured by Alexander. Alexander treated them with respect and gallantry, according them the status of honored guests.

The gates of the Near East lay open before Alexander. However he did not pursue Darius. He had another objective which took top priority. It was of strategic importance for Alexander to control the naval bases from which the Persian fleet operated in the Mediterranean. So instead of continuing East, he marched south to Phoenicia.

The Persian fleet was manned by Phoenician crews, and the kings of the Phoenician cities were at the time at sea with the fleet, so each individual Phoenician city-state had to decide whether to come to terms with Alexander or to try to resist him.
Only Tyre, built on an island, held out for any length of time, and Alexander dealt severely with the Tyrians when he finally took the city after a seven-month siege. According to Quintus Curtius (4.4.17), 2,000 Tyrians were nailed to crosses along a great stretch of the shore and 30,000 were sold into slavery.
A more detailed description of Alexander's conquest of Phoenicia is given here

After leaving Phoenicia, Alexander continued south along the coast, by-passing Jerusalem, but taking Gaza. When he reached Egypt he was greeted as a conqueror. He made a special pilgrimage into the desert to the shrine of Zeus Ammon, where he claimed that the god appeared to him in a dream and acknowledged him as his son - a claim which was corroborated by the high priest of Zeus Ammon.
While in Egypt Alexander founded the city of Alexandria at the mouth of the Nile. Over the course of time Alexandria became the commercial and intellectual center of the East Mediterranean.

In the spring of 331 BC Alexander left Egypt and the Mediterranean, marching north-east to strike into the heart of the Persian empire. Darius had assembled another army and awaited Alexander at Arbela, near Nineveh. Alexander defeated Darius again, and again Darius fled eastward, this time toward the Caspian Sea and the region of Media and Bactria.
Alexander did not immediately pursue Darius, but followed the Tigris River into Babylonia, the central seat of the Persian empire and its richest region. From there he proceeded to Susa, then to the royal city of Persepolis with its enormous treasures. While at Persepolis he set fire to the city. The sequence of events is not clear. The geographer Strabo (15.6) states that Alexander fired the city in revenge for the burning of Greek temples by Xerxes during the Graeco-Persian wars. Plutarch (38.1-4) gives another version saying that the fire was started during a drunken revelry but was extinguished by order of Alexander who regretted the deed.

Then Alexander took up the pursuit after Darius, from Ecbatana to the Caspian Sea. The Persian empire was crumbling. Darius was deserted by his generals and by his troops. Darius' cousin, Bessus, seized the opportunity (as he thought) to ingratiate himself with Alexander. At night Bessus and a few followers burst into Darius' tent, tied him up with ropes and carried him to his chariot and drove to Bactria. Bessus hoped to offer the Persian king as a hostage in exchange for Alexander's recognition of Bessus as ruler of the eastern satrapies of the empire. Alexander followed in hot pursuit. In order to escape, Bessus galloped up to the royal chariot, stabbed Darius to death and got away. When Alexander caught up to the royal chariot, he found only the corpse of Darius. Alexander looked down on his fallen foe with compassion, and covered his body with his purple cloak.

Eventually Bessus was captured and brought in chains to Alexander. Due to the nature of the crime, Alexander had him sentenced by Persian judges, not by himself. Bessus was found guilty of rebellion against his king. His nose and ears were cut off and he was led to Ecbatana where he was crucified on a tree.
Alexander continued his march eastwards, through Bactria and Sogdiana, putting down rebellions and founding Greek cities. During this time he captured Roxanna, the beautiful daughter of Oxyartes, king of Bactria, and married her. Then he crossed the Hindu Kush and entered India.
One of the principalities, situated between the Hydaspes and Ascenines, was ruled by Porus. Alexander crossed the Hydaspes, Porus held the opposite bank with a powerful force and two hundred elephants. During the battle Porus was wounded and fell into Alexander's hands. However Alexander made the defeated king his friend.
Plutarch (61.1) says that it was at this time that Bucephalus died, wounded in battle. Other sources say that the horse died of fatigue and old age. Alexander was overcome with grief. He built a tomb for the horse on the banks of the Hydaspes river, and founded a city there which he named Bucephalia in his memory.
Alexander wanted to continue East into India, but his army refused to go further, and mutiny began to break out, so Alexander eventually agreed to turn back. He built a fleet of ships, and sailed down the Indus, with some of his army on the ships, and some marching on either side of the river, taking part in heavy fighting against local towns.

For the route back home, Alexander divided his army into three parts. The weak and injured were to take a northern route, with the baggage trains, elephants, and armaments, under the leadership of Craterus. Another of his generals, Nearchus, was to take the ships and explore the sea route back to the Persian Gulf.
Alexander himself determined to take the challenge of crossing the Gedrosian desert - what is now called Baluchistan - which was reputed to be a march of death which few could survive. Alexander's crossing of the Gedrosian desert was disastrous. Many of his men died from lack of food and water; others were killed by a sudden flash flood while they were camping in a wadi. The terrain was worse than Alexander had expected, and he was unable to march near the coast to set up supply depots for Nearchus as they had planned.. However, eventually Alexander and Nearchus managed to meet up again and reached Susa.
As part of his pacification plan for Persia, Alexander arranged for his men to marry Persian women - 80 of his officers and about 10,000 of his soldiers took native wives, while Alexander and his friend Hephaestion married two of Darius' daughters. Shortly after this Hephaestion died, and Alexander gave way to a prolonged period of extravagant mourning which culminated in his demand that Hephaestion be granted the status of a Hero, and that he himself be accepted as a god and worshipped as such. He was planning an expedition to the Caspian Sea, and further exploration of the Sea route to India when he became ill after a long banquet and drinking session. He died ten days later, at the age of 33, on June 13, 323 BC.
His general Ptolemy took Alexander's body to Alexandria in Egypt.

Initially, his generals appointed as joint "kings" Alexander's feeble-minded half-brother, Philip Arrhidaeus, and the son whom Roxana bore him posthumously, Alexander IV, "Aegus". The two "kings" were put under the guardianship and protection of Perdiccas, Peithon and Antipater, in succession. Upon the death of Antipater, Roxana fled with her child to Epirus to seek the protection of Olympias, Alexander's mother. She was taken there by Polyperchon, an officer close to Alexander to whom Antipater had delegated his power. From Epirus Polyperchon accompanied Olympias, Roxana and the boy to Macedonia. All three fell into the hands of Antipater's son, Cassander. Olympias was put to death, and young Alexander and his mother were kept under close arrest. They were murdered in 310-309 BC by order of Cassander. The dynasty of Alexander the Great came to an end with the death of Alexander IV Aegus, his son, barely twelve years of age.

 

Eye witness accounts of the daring exploits of Alexander unfortunately do not exist. What we know about him comes from secondary sources. Arrian (first century B.C.) refers to the works of Alexander's general, Ptolemy, and Aristobolus, whose writings are lost. Diodorus Siculus (first century B.C.) and Quintus Curtius (first century A.D.) no doubt had access to earlier histories that have not survived.

Very few likenesses of Alexander have come down to us. Plutarch (4.1) records that the finest statues of Alexander were made by Lysippus, who was the only sculptor tolerated by the young man. Even the inclination of Alexander's head a little on one side towards his left shoulder was reproduced in marble and was imitated afterwards by the generals who succeed him in an effort to emulate him. Coins minted during Alexander's reign have on the obverse the head of the god Heracles wearing the lion skin. Portraits of Alexander only appear later on the third century BC coins made by Lysimachus, king of Thrace. These show Alexander as a god wearing the sacred horns of the Egyptian god Ammon.