These early Greek plays often focused on themes of fate, morality, and the struggles of the human condition. Theater continued to thrive during the Roman Empire, where performances were held in grand theaters such as the Colosseum. Roman plays often featured comedic elements and were a popular form of entertainment for the citizens of Rome. After the fall of the Roman Empire, theater continued to evolve throughout the Middle Ages in Europe. The church played a significant role in influencing the development of theater during this time, with religious plays known as mystery plays being performed in churches and town squares.