This is part of a ceramic tile floor found in a fourth-century Roman Villa in England. Life was prosperous in Britain under the Romans, even at this late date.

This symbol of the Alpha and Omega (God as the beginning and the end) in conjunction with the Chi Rho (first two Greek letters of "Christ") was one of the most widely used symbols of Christianity.

Constantine and some of his soldiers claimed to have seen the Chi Rho as a vision in the sky during the march on Rome in 312. They took this as a sign of divine favor, took over the Roman Empire, then legalized Christianity -- thus ending centuries of Roman persecutions against Christians. (British Museum, Photo by M. Markowski)