The Sassanid Empire was a powerful Iranian dynasty that ruled a vast area of the ancient world from 224 to 651 CE. During their rule, the Sassanids ushered in a period of great cultural and political achievement in the region. Among the most significant contributions of the Sassanid Empire were the revival of Iranian imperial traditions and the patronage of Zoroastrianism, the official religion of the empire; the development of a sophisticated court and legal system; the establishment of a powerful military; the promotion of trade and commerce; and the expansion of the arts and sciences. The Sassanids also built many impressive monuments, including palaces, fortresses, and grand city gates. These grand structures were often decorated with intricate stone carvings and elaborate mosaics, and the ruins of some of these monuments still stand today. The Sassanids left a lasting impression on the region and their legacy is still felt today.