The term "Sassani" refers to the Sassanian Empire, which was a significant Persian empire that existed from 224 to 651 CE. It was founded by Ardashir I after defeating the Parthian Empire. The Sassanian Empire is known for its achievements in art, architecture, and science, as well as its role in the development of Zoroastrianism. The Sassanian Empire was characterized by a centralized government and a strong military. It expanded its territory to include parts of the Middle East, North Africa, and Central Asia. The empire eventually fell to the Arab Muslim conquests, leading to significant cultural and religious changes in the region.