Alexander was born in 356 BC, the son of King Philip II of Macedon, which was north of classical Greece. He was personally tutored by Aristotle, and after his father was assassinated, Alexander became king at the age of 20.
He proceeded to take his giant army and wreak havoc in the Persian empire, liberating one city after another, until he eventually conquered the entire Persian empire.
He arrived in Egypt in 332 BC and they welcomed him as their liberator. The Egyptian natives and Greek merchants who lived in Egypt were not big fans of Persian rule, and were happy to have someone more Greek in charge.
Egypt was a very wealthy nation, with a rich history and culture, a lot of knowledge in subjects like astronomy and mathematics, and with the great food source of the Nile. If you were trying to conquer the world, Egypt would be a top place on your list.
Alexander wanted to build a large Greek city on the Egyptian coast with easy access to the Mediterranean. It would be a Hellenistic centre in Egypt, and be a physical link between Egypt and Greece. It would also have the honor of being named after him.
He sent his men to find a spot for the new city, and they found a good one. Work was just about to begin when he had a dream. In his dream he saw an old man speaking the lines “Then there is an island in the stormy sea, In front of Egypt; they call it Pharos”.
He immediately woke up, went to Pharos, and realized that it would be an amazing location. By joining the island of Pharos to the mainland, they would be able to create two great harbors.
The city plans were laid out with flour since they didn’t have any chalk available. This led to an issue where as soon as they dropped some flour to mark things out, birds would come eat the flour.
Some men thought this was a bad omen that the city lines were being destroyed as they laid it out, but Alexander’s favorite seer said it showed that Alexandria would one day feed the world.
With the work underway, Alexander left to go to the desert shrine of the god Amun at Siwa to see a popular and respected oracle. The oracle kind of maybe said that Alexander was actually a child of the god Amun.
Greeks were very skeptical of this claim, but in Egypt religion was a foundation of their society, and this claim made Alexander a more legitimate ruler of Egypt.
The oracle encouraged Alexander to continue conquering the world, and so he continued destroying the Persians and getting more land. Finally in Babylon, at the age of 32, he died of a fever (and/or poison).
And that was the beginning of the end of his great kingdom. It would soon splinter off into different factions that fought among themselves. One of those factions outlasted all the others, and that was the one started by Ptolemy, Alexander’s BFF, centered in the city of Alexandria, Egypt.