Arab conquest of Iran in the context of "Iranian Intermezzo"

The monarchs of Iran ruled for over two and a half millennia, beginning as early as the 8th century BC and enduring until the 20th century AD. The earliest Iranian monarch is generally considered to have been either Deioces of the Median dynasty (c. 727–550 BC) or Cyrus the Great of the Achaemenid dynasty (550–330 BC). The last Iranian monarch was Mohammad Reza Pahlavi of the Pahlavi dynasty (1925–1979), who was overthrown in the Iranian Revolution. Since then, Iran has been governed by theocratic supreme leaders.

In classical antiquity, Iran reached the peak of its power and prestige under the Achaemenid Empire, which stretched from Egypt and parts of Southeast Europe in the west to the Indus Valley and parts of Central Asia in the east. By 323 BC, the Achaemenid Empire's territories had been conquered by the Macedonian Empire during the Wars of Alexander the Great, bringing Iran into the Hellenistic sphere. In the Wars of the Diadochi, the Seleucid Empire (305–129 BC) assumed control of Iran. Native Iranian rule was revived with the establishment and expansion of the Parthian Empire (247 BC–224 AD) and then the Sasanian Empire (224–651), which existed until the Arab conquest of Iran.

Istakhr (Middle Persian romanized: Stakhr, Persian: استخر, romanized: Estakhr) was an ancient city in Fars province, 5 kilometres (3 mi) north of Persepolis in southwestern Iran. It flourished as the capital of the Persian Frataraka governors and Kings of Persis from the third century BC to the early 3rd century AD. It reached its apex under the Sasanian Empire (224-651 AD), and was the hometown of the Sasanian dynasty. Istakhr briefly served as the first capital of the Sasanian Empire from 224 to 226 AD and then as principal city, region, and religious centre of the Sasanian province of Pars.

During the Arab conquest of Iran, Istakhr was noted for its stiff resistance, which resulted in the death of many of its inhabitants. Istakhr remained a stronghold of Zoroastrianism long after the conquests, and remained relatively important in the early Islamic era. It went into gradual decline after the founding of nearby Shiraz, before being destroyed and abandoned under the Buyids. Cursorily explored by Ernst Herzfeld and a team from the University of Chicago in the first half of the 20th century, much of Sasanian Istakhr remains unexcavated.