I've always considered the last Roman vs Persian war the first world war. It lasted nearly 30 years, saw action, territory changes, and troop movements from Western Europe, through Africa, and the Middle East.

At the onset the Eastern Romans still held onto small portions of Western Europe all the way to Syria and Egypt, meanwhile Sassanid Persia stretched all the way to modern Afghanistan. By the end of the war, both states had their demographics depleted from war, changing the world forever and allowing for the rise of Islam.

You had the formation of coalitions led by the "super" powers of the time, with the Romans having Armenians, the Turkic Khanate, and a subset of Arabian nomads in their corner, while another set of Arabians, the Avars, and the Slavs were with the Persians. All the meanwhile you had opportunistic factors like the Visigoths in Spain.

There was even a civil war on the Roman side during all of this.

Anyways I find this part of history super interesting and it would make Game of Thrones look like child's play.