The Roman era continued for many years, even after the fall of the western Roman Empire; leaving only the Eastern Empire with it's capital in Constantinople (modern day Istanbul). Due to the change of locality, being in the region of Byzantium, this time period has been called the Byzantine era.
Age: 400 CE
Excavated: Tell El-Farah
Purchased: From archaeological assistant on the excavation
Tesserae were floor tiles. These little stones, typically of varying colors were arranged to create beautiful designs such as those below. Tesserae have been used to create tiled floor designs for thousands of years. Unlike those in the pictures, these Tesserae were not found in-situ. In other words, there's not a beautiful mosaic floor out there with two tiles missing. Well, I guess there could be, but not missing these two tiles.