He was born in 356 BC and became the king of Macedonia in 336 BC at the age of twenty. He had a fair complexion and had the figure of a real athlete as he received the best military training and education.
As soon as he became the King of Macedonia, he reduced taxes on the Macedonian people promising them that he would follow the political system of his father, Philip II.
He summoned the Greek polises to meet him to renew their loyalty for him but some Greek cities – led by Sparta – refused to meet him. Before taking any decision against them, on the borders of Macedonia, a trouble had broken out by the semi-private tribes, Ghol. After preparing the army, Alexander III defeated them and restored law and order. During his fight against these tribes, rumors spread in Greece that Alexander, the Great was killed. Such rumors arouse a number of Greek polises – headed by Thebes – to revolt against Macedonia. When Alexander III returned to his capital and knew about the Greek revolution, he marched with his army very fast until he reached Thebes and surrounded it. He asked the polis to surrender and to join Macedonia once more, but the citizens refused. With their refusal, he didn’t wait; rather, he attacked the polis without giving any chance for his army to have a rest. By morning, all men were killed and both women and children were taken as slaves. He destroyed the whole city with the exception of its temples. When the news of Thebes reached the other Greek polises, they declared their loyalty for Alexander, the Great. Once more, he prepared a joint army of Macedonian and Greeks headed by him and went towards eastwards to fight the Persians in 334 BC.
The first encounter between Alexander III and the Persians was a battle near a river called Eranicus in Asia Minor. The Persian army was led by a Persian satrap. After a short-timed battle, Alexander III defeated the Persian army and defeated their forces towards Persia. Then, the news reached Alexander III about the presence of another Persian army at Issus on the northern Syrian coast under the command of the Persian king. So Alexander III moved with his army to Issus meeting for the second time with another Persian army. After a fierce battle, he succeeded in defeating the Persian army and the defeated forces escaped to Persia.
At this time Alexander had two options to choose from:
1- To follow the defeated Persian army in order to finish it off before getting improved.
2-To occupy the east of the Mediterranean Sea and Egypt to prevent the strong Persian fleet there from receiving orders or supplies and thus, this fleet could be defeated without having to fight them.
Alexander chose the second option by occupying the east of the Mediterranean Sea and continuing his march to Egypt in 332 BC. Egypt at that time was under the 7-year second Persian occupation.
The Egyptian welcomed the arrival of Alexander the Great believing that he came to help them getting out of the Persian occupation but Alexander III had another idea in his mind. He was crowned as the new Pharaoh of Egypt by the priest of god ptah in their famous temple H.t-k3-ptH at Memphis then he decided to consult the famous oracle of god Amun at Siwa Oasis. He followed the Canope branch of the Nile until he reached the Mediterranean Sea then headed west to Marsa Matrouh and south to Siwa Oasis. Reaching the Mediterranean Sea, he noticed the strategy of the site of the Ancient Egyptian village that was located there so he ordered his chief architect, Dinocratis, to build a new city carrying his name and so the city of Alexandria was found. Then he reached Siwa Oasis and consulted the oracle of Amon. He sent a letter to his mother Olympius telling her that she would be the first one to know what Amon told him. Alexander the Great never returned back to Memphis and he appointed Clemenes (a Greek banker) from Naucratis a chief administrator of Egypt.
Alexander III left Egypt and continued his conquest against the Persian Empire that he succeeded to demolish. Alexander the Great married to a Persian princess called Roxona. On the night of his wedding, 5000-9000 Greek and Macedonian officers and soldiers married to Eastern women, among them was Ptolemy, Son of Lagos. This night is known in the history as the great wedding night.
Alexander III continued his conquest until he reached the Indian borders but his army refused to proceed any further, so; he was forced to retreat back. On his way back at Babylon, he fell in suffering from swamp fever. After a short period of the illness, Alexander III died in 13th of June 323 BC, leaving behind him his pregnant wife, Roxona, and his half brother, Phillip Arthemidis.
After the death of Alexander the Great, his army's leaders decided to hold a conference (which is known as the Babylon conference) to decide the future of the newly created empire. After a long debate, they reached the following decisions:
1- Alexander III's body should be mummified.
2-His mummy should be buried at Pella, the capital of Macedonia. 3-Pella should be the capital of the new empire.
4- Alexander III should be succeeded by his half brother, Phillip Arthemides, and his son (if Roxona gave birth to a baby boy). In fact three months later, Roxona gave birth to a baby boy called Alexander IV.
5-Minor kings should be under the regency of the army's oldest ruler who was called Predicass.
The countries of the Empire were divided among the other leaders of the army to rule them as satraps in the name of the family of Alexander the Great.