the Early Assyrian ( 2600-2025 BC), Old Assyrian ( 2025-1364 BC), Middle Assyrian ( 1363-912 BC), Neo-Assyrian (911-609 BC), and post-imperial (609 BC- AD 240) periods, based on political events and gradual changes in language. Assur, the first Assyrian capital, was founded 2600 BC,