Sassanid Empire (Fidem Pacis)

The Sassanid Empire (AD 224-949) was the period of Iranian history when the country was ruled by the Sassanid dynasty from Persis. It endured the era of migrations relatively intact, outlasting several of its civilized neighbours, and played an important role in limiting the spread of Islam eastwards, just as it had limited the spread of Christianity centuries earlier.

The empire was founded by Ardashir I, who claimed descent from the Achaemenid dynasty of antiquity. In 224 he overthrew the Arsacid Parthians and established a new Persian Empire that would rule the region for the next seven hundred years. Before long the Sassanids had established the same rivalry with Rome that their predeccessors had, resulting in numerous conflicts between the two empires over the centuries.

From 602-628 Persia fought a long and bloody war with Rome, provoked by the usurpation and assassination of Shah Khusrau II's friend and ally, the Emperor Maurice. The war critically weakened both empires, leaving them vulnerable to the emerging Talibid Caliphate. However, in 632 the Emperor Heraclius converted to Islam, allying with the Caliphate and succeeding in restraining its expansionist tendencies.

In 634 Persia attacked the Beni Lakhm, an Arab people who previously been Persian vassals but had recently rebelled and deserted to the Caliphate. When the Caliphate tried to assist the Lakhmids it only succeeded in provoking a full-scale war, that eventually dragged in Rome and Axum and resulted in a devastating Persian defeat. Mesopotamia was lost to Rome, and Shah Yazdegered III was captured, which would trigger decades worth of civil wars between rival branches of the dynasty fighting for the throne.