The very early Romans wore a toga.  It looked like a white sheet 9 yards long, and had to be arranged very carefully, in a stylish way. The toga was inconvenient, and people felt the cold when they wore it. Togas fell out of style rather early. Even very early emperors had to legislate the wearing of togas by at least senators. Eventually, everyone gave up. The Romans switched to tunics, which looked like long t-shirts, and were made of linen or wool. Sometimes, they worn trouserlike affairs. Tunics were much warmer and much more practical.