The kingdom, centered in present-day northern Iran, was ruled by Atropates' descendants until the early 1st-century AD, when the Parthian Arsacid dynasty supplanted them.

[3] Atropatene was the only Iranian region to remain under Zoroastrian authority from the Achaemenids to the Arab conquest without interruption, aside from being briefly ruled by the Macedonian king Alexander the Great (r. 336–323 BC).

Consequently, the king of Atropatene, Artabazanes, accepted the ascendency of Seleucids and became dependent on it; on the other hand, interior independence was preserved.

[11] The Iranologist Touraj Daryaee argues that the reign of the Parthian monarch Vologases V (r. 191–208) was "the turning point in Arsacid history, in that the dynasty lost much of its prestige.

"[12] The people of Atropatene (both nobility and peasantry) allied themselves with the Persian Sasanian prince Ardashir I (r. 224–242) during his wars against Vologases V's son and second successor Artabanus IV (r. 216–224).

[3] Ardashir I and his son and heir Shapur I (r. 240–270) are depicted in a rock relief near Salmas, possibly a testimonial to the Sasanian conquest of Atropatene.

[15][16][17] The main Achaemenid hub in Atropatene was Ganzak (from Median: Ganzaka, meaning "treasury"), which presumably served as the capital of Atropates and his successors.

[20] Atropatene was the only Iranian region to remain under Zoroastrian authority from the Achaemenids to the Arab conquest without any interruption, aside from being briefly ruled by the Macedonian king Alexander the Great (r. 336–323 BC).

[21] Under the Atropatids, the region successfully managed to gain a dominant place in Zoroastrianism, which would continue into the Sasanian period, whose monarchs favored Median traditions over that of the Parthians.