Controversy surrounds how ‘great’ Alexander really was, but what is certain is that his empire was vast, spreading all the way to the Hindu Kush.  When Alexander died in 323 BC his empire was fiercely fought over by his generals and close advisors.  The Seleucid empire was the largest of all the successor states that formed after his death. Just after Alexander’s death, Seleucus was not given a portion of the empire, instead he was relegated to oversee the Companion Cavalry under Perdiccas, the regent of Macedon.  Not satisfied with his outlook, Seleucus began the battle for his own piece of the empire. First in 321, he was one of the people who took part in the assassination of Perdiccas. With the regent gone there was a meeting to repartition the empire and Seleucus was assigned as satrap of Babylon. This brought him into contact with Antigonus Monophthalmus (Antigonus “the one-eyed”) who some five years later started to question his stewardship.  Seleucus fled to Ptolemy, who made him commander of his fleet in Egypt. After the defeat of Demetrius, the son of Antigonus in 312 BC in Gaza, Seleucus received permission from Ptolemy to overtake the city of Babylon. This important date marks the beginning of the great Seleucid empire.