The Greek Empire is an alternate timeline that the Point of Divergence is what if Alexander the Great's son, which he did have in OTL, had a much bigger impact since his father died at an old age at the time.
Alexander I "the Great" of Greece
After having to manage a massive hangover due to him drinking very heavily the previous week, Alexander re-organized his army and hired new generals to replace his old ones. In August of 323 BC, his first son Alexander was born. Once Alexander was finally ready managing his army, he declared war on some of the Arabian nomads in September of 323 BC. His army charged into the battlefield, killing almost 500 troops in just 3 hours. They turned around and charged again, forcing surrender on one of the Arabian troops. Then, thinking they would be able to pull it off one more time, Alexander went up into the hills of Persia and waited about 2 hours. Once they got close enough, he charged onto their army and instantly killed their ruler. They instantly surrended after that, leaving Alexander with almost all of Arabia, which only took him 4 months. He then took a break in military and focused on his own kingdom. He formed the Empire of Greece in 321 BC. His second son, Dionysos, was born in the same year. After 2 years of no campaigning, Alexander declared war on the bordering Indian nomads in February of 320 BC. He finished the campaign in 1 month. This would be Alexander's last major war. Soon after, his third and last child/son, Philip was born in 318 BC. After a bunch of years, Alexander died at age 60 in 296 BC.