Atropatene (; ), also known as Media Atropatene, was an ancient Iranian kingdom established in by the Persian satrap Atropates. 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. It was conquered by the Sasanians in 226, and turned into a province governed by a marzban ("margrave"). 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 (). The name of Atropatene was also the nominal ancestor of the name of the historic Azerbaijan region in Iran. Name According to Strabo, the name of Atropatene derived from the name of Atropates, the commander of the Achaemenid Empire. As he writes in his book “Geography”: "Media is divided into two parts. One part of it is called Greater Media, of which the metropolis is Ecbatana. The other part is Atropatian Media, which got its name from the commander Atropates, who prevented also this country, which was a part of Greater Media, from becoming subject to the Macedonians". From the name of Atropates, different forms of the name of this country such as Atropatene, Atropatios Mēdia, Tropatene, Aturpatakan, Adarbayjan were used in different sources. Nevertheless, medieval Arab geographers suggested another version associating this name with Adorbador (the name of a priest) that means “guardian of the fire”. History In 331 BC, during the Battle of Gaugamela between the Achaemenid ruler Darius III and Alexander the Great, Medes, Albans, Sakasens, Cadusians fought alongside the army of the Achaemenid Great King in the army of Atropates. After this war, which resulted in the victory of Alexander the Great and the fall of the Achaemenid Empire, Atropates expressed his loyalty to Alexander. In 328-327 BC, Alexander appointed him governor of Media. Following the death of Alexander the Great in 323 BC, the Macedonian's conquests were divided amongst the diadochi at the Partition of Babylon. The former Achaemenid satrapy of Media was divided into two states: The greater (southern) part – Media Magna was assigned to Peithon, one of Alexander's bodyguards. The smaller (northern) region, which had been the sub-satrapy of Matiene, became Media Atropatene under Atropates, the former Achaemenid governor of all Media, who had by then become father-in-law of Perdiccas, regent of Alexander's designated successor. Shortly thereafter,