Following the overthrow of the
Median Empire, all of what is today Azerbaijan was invaded by the Persian king Cyrus the Great in the 6th century BCE. This earliest Persian Empire had a profound impact upon local population as the religion ofZoroastrianism became ascendant as did various early Persian cultural influences. Many of the local peoples of Caucasian Albania came to be known as fire worshipers, which may be a sign of their Zoroastrian faith.
This empire lasted over 250 years and was conquered later by
Alexander the Great and led to the rise of Hellenistic culture throughout the former Persian Empire. The Seleucid Greeks inherited the Caucasus following Alexander's death in 323 BCE, but were ultimately beset by pressures from Rome, secessionist Greeks in Bactria, and most adversely theParthians (Parni), another nomadic Iranian tribe from Central Asia, which made serious inroads into the northern eastern Seleucid domains from the late 4th century BCE to the 3rd century BCE and this ultimately allowed local Caucasian tribes to establish an independent kingdom for the first time since the Median invasion.