The history of Iran is intertwined with the history of a larger region known as Greater Iran, comprising the area from Anatolia in the west to the Indus river and the Syr Darya in the east, and from the Caucasus and the Eurasian Steppe in the north to the Persian Gulf and the Gulf of Oman in the south. Central to this area is Iran, commonly known until the mid-20th century as Persia in the Western world.
Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 4000 BC. The south-western and western part of the Iranian plateau participated in the traditional ancient Near East with Elam (3200–539 BC), from the Bronze Age, and later with various other peoples, such as the Kassites, Mannaeans, and Gutians. Georg Wilhelm Friedrich Hegel calls the Persians the "first Historical People". The Medes unified Iran as a nation and empire in 625 BC. The Achaemenid Empire (550–330 BC), founded by Cyrus the Great, ruled from the Balkans to North Africa and also Central Asia, spanning three continents, from their seat of power in Persis (Persepolis). It was the largest empire yet seen. They were succeeded by the Seleucid, Parthian, and Sasanian Empires, who successively governed Iran for almost 1,000 years and made Iran once again a leading power in the world. Persia's arch-rival was the Roman Empire and its successor, the Byzantine Empire.
The Iranian Empire proper begins in the Iron Age, following the influx of Iranian peoples. Iranian people gave rise to the Medes, the Achaemenid, Parthian, and Sasanian Empires of classical antiquity.
Once a major empire, Iran has endured invasions too, by the Macedonians, Arabs, Turks, and Mongols. Iran has continually reasserted its national identity throughout the centuries and has developed as a distinct political and cultural entity.
The Muslim conquest of Persia (633–654) ended the Sasanian Empire, and was a turning point in Iranian history.
