So many mosaics and tessellated pavements survive that we almost take them for granted with their gently-muted colours and sometimes strange messages from the ancient world. It’s an art form that continues and is enjoyed to the present day but reached glorious highlights in Byzantium, Ravenna and Sicily in the Middle Ages. This lecture, however, concentrates on the mosaics (mainly floor mosaics) made by our Greek and Roman ancestors right across their empire. It’s a remarkably durable art form being designed to be walked on or to have furniture standing on it. The designs might be advertisements or messages of warning or welcome, but mainly they are decorative. Some are distinctly pagan, others Christian, but many show charming, not to say revealing, vignettes of everyday life as it was lived up to two millennia ago.