Iran enjoys one of the richest historical lineages of any modern state stretching back several thousand years. This history can be broadly divided into three epochs: the pre-Islamic ancient period (c559 BC to 651 AD); the Islamic era (651 AD to 1800 AD); and the modern era, defined by its encounter with Western modernity from around 1800.

The pre-Islamic ancient period

‘Iranian’ history proper begins with the migration of the Iranian tribes from Central Asia onto what is now known as the Iranian plateau in the 2nd millennium BC. But organised human settlement developed much earlier and Elamite civilisation in south western Iran – southern Iraq today – emerged in the third millennium. By the 1st millennium BC, two distinct Iranian states emerged in the form of the Medes and Persians and their emphatic entrance onto the world stage began with the accession of Cyrus II in 559 BC.

The Achaemenid Persian Empire grew to become the largest contiguous land empire then known to man, impressing both friend and foe alike with its relatively benign administration drawing on religious ideas that would later be associated with Zoroastrianism, the pre-Islamic religion of Iran identified with the mantra “good words, good thoughts and good deeds”. It looms large in the Western imagination because of its failed attempts to conquer the Greek states and its subsequent defeat at the hands of Alexander the Great some 150 years later in the 330s BC. Hellenized rule under Alexander’s successors – the Seleucids – lasted a century until the arrival of a new Iranian dynasty from the east, the Parthians.