Persian and Sassanid, what's the difference

Persia

The Persian empire is one of the most important and iconic nations in the Middle-East. Spamming from Northeast Africa to India's border and Anatolia, the empire was one of the greatest of its time. Small fact, its real name is the "Achaemenid Empire" since it was the name of its only dynasty. It collapsed when Alexander decisively defeated Darius III at the Battle of Gaugamela, shattering the Persian king's army.

Sassanid

Another great empire shared the same localization as the Persians of old. This empire was known as the Sassanid. Their territories covered the Eastern half of the Persians lands. Although its northern part wasn’t as far-reaching, it did incorporate some of Saudi Arabia's coastline. They did not possess the region of Anatolia, Egypt and the coastland in Between, being the heart of their arch-rival, the Byzantines.

Similarities

The two empires shared more than common territories. Their art styles were extremely similar. They shared the same dominant religion, Zoroastrianism and much more. By the way, this religion is still practiced today and is the oldest living one! Even their rulers were called the same, refer to as King of Kings or Shahanshah in the Sassanid case. All of those resemblances lead many to believe that they were the same empire with different names.

Differences

However, this presumption isn’t entirely correct. We first are going to remove the elephant in the room. Around 700 years separates the two nations. The Achaemenid fell in 486 BC, while the Sassanid rose in 224 AC. This is almost as long as the Byzantine Empire's entirety and the Eastern roman’s one would have time to live and die twice. This is a very long time, especially in the Antiquity where people tend to die much younger than today. Despite being called Neo-Persians, The Sassanids never considered themselves as such, there so Persia died alongside Darius III.