When did alex the great empire change?

Alexander the great's empire began to change significantly after his death in 323 BCE. His untimely passing left a power vacuum, leading to the Wars of the Diadochi, where his generals, known as the Diadochi, fought for control over different parts of the empire. This struggle resulted in the fragmentation of his vast empire into several Hellenistic kingdoms, including the Seleucid Empire, the Ptolemaic Kingdom, and others, which marked the decline of unified control and the beginning of a new political landscape.