This appears to be an early medieval cast bronze mortar but I would like additional opinions. Its dimensions are correct--about 6" high, and about 8.75" at the rim, flaring out from a smaller base. Around the sides are six images that appear to be the four evangelists, Moses with tablets, and the Madonna with child. All are seated beneath early Romanesque arches. The Madonna is enthroned facing forward with the Christ child in her lap also facing forward with two figures on either side, a version that is much more common from the 11th century and earlier. There is significant wear, a smoothing of the images with loss of detail and the patina seems correct. Stress fracture lines on the base and wear at the bottom of the mortar suggest many years of pounding with a heavy (probably bronze or iron) pestle. The lack of handles or rings also appears consistent with the very earliest mortars and the casting lines on the side are also found in very early medieval bowls. This appears to be authentic and I am guessing that it was used in a religious hospital, but I would like the opinion of others with greater knowledge of early medieval objects.