sentences:  The Romans only developed fired clay bricks under the Empire, but had previously used mudbrick, dried only by the sun and therefore much weaker and only suitable for smaller buildings.Development began under Augustus, using techniques developed by the Greeks, who had been using fired bricks much longer, and the earliest dated building in Rome to make use of fired brick is the Theatre of Marcellus, completed in 13 BC.The process of drying bricks in a kiln made it so these bricks would not have cracks in them when they dried.