Found in 1845 during renovation work on the choir of the cathedral of Santa Maria in Acqui. The figures, the decoration, and the scripts are made of contrasting black and white stone tesserae like those in floor mosaics of Roman times. Unfortunately, the mosaic carpet is so fragmented that it is impossible to reconstruct the narrative, which originally extended over the whole area of the chancel. We can however make out a winged figure, a bowman, and a camel being led by a man, amongst other things. The inscription is important, for it pays tribute to Bishop Guido who was responsible for finishing the reconstruction of the cathedral, which was consecrated in 1067.