In Cormac's chapel at the Rock of Cashel we get the square tower such as later Comacines used from the sixth to the tenth centuries, with the double-arched window of the period; and the church beside it has the same signs. Here are the string courses supported by the row of little arches, the projecting apse, and the double-light windows, with only that same northern desideratum—the high gable and sloping roof. Cormac was an early Bishop of Cashel, who was killed in 907 A.D.
Look at the shrine of the Bell of St. Patrick, which I presume dates from about the eighth century, i.e. the time of Fredianus, and you will see a fine collection of Comacine intrecci or interlaced work in sculpture. As for the crosses of Ireland, one may trace in them the development of Comacine work, from the early Christian Roman style to the mediæval Lombard.
The beautifully illustrated article in the Studio for Aug. 15, 1898, by J. Romilly Allen, F.S.A., shows the whole line. In the earliest form of Irish cross, i.e. that where the cross and Christian symbols are merely cut into the face of a slab of stone, such as in the cross at Reask, Co. Kerry, we see precisely the primitive style of art shown in the Catacombs. The "Gurmarc" stones have their prototype in the earliest Longobardic carving, such as the pluteus of Theodolinda's first church at Monza. The smaller of the three inscribed circles has an even more advanced Comacine intreccio enclosed within the circle, while the cross of Honelt at Llantwit Major (Fig. 5) has a splendid Comacine knot such as one sees on every Longobardic church, placed beneath a very Byzantine geometrical design in which circles, crosses, triangles, and three-fold knots are marvellously intermingled. These are all stones merely incised, and foreshadow the predilection of the Irish converts for the symbolism of the time, the cross of Christ within the unending circle of eternity. The next development shown by Mr. Romilly Allen is the upright cross slab at St. Madoes in Perthshire, where the cross and the circle are in distinct relief and not merely incised. Here, instead of the circle enclosing the Greek cross, it has become subordinate, and is placed behind the arms of a Latin cross. In fact a complete Irish cross in relief. But how is it adorned?—with splendid Comacine intrecci, and all the symbolism so familiar to us in early Italian art. Here are the coiled serpent and the dove above, with the four mystic beasts of the Apocalypse below, two on each side of the stem of the cross; and the workmanship and designs are literally identical with those of the sculptures on the façades of the first church of S. Michele at Pavia, and S. Zeno at Verona, and that of S. Pietro at Spoleto, all of the fifth and sixth centuries. (Spoleto church was rebuilt in 1329, but the ancient Lombard sculptures around the doorway were preserved.)
Door of the Church of S. Zeno at Verona. A.D. 1139.
By the ninth and tenth centuries the Irish cross had reached its full development. It was no longer a sign on a slab, but a beautiful upright sculptured cross, with a circle crowning it like a halo, and suggesting the eternity of the human cross of our Saviour. And here again the art is precisely that of the Italian sculptors. There was a cross of earlier date than either the cross of King Flami at Clonmacnoise, King's County, A.D. 904, or the cross of Mucreadach at Monasterboice, Co. Louth, A.D. 924, in the Roman Forum, of which the shape and ornaments are similar to both of them. The cross of SS. Patrick and Columban at Kells has, too, all the marks of the Comacine work in the eighth and ninth centuries, as one sees it in the oldest churches at Como and Verona, at Toscanella and Spoleto. All these things being considered, I think Irish archæologists would do well to work up the undoubted connection of the early Irish missionaries with Italy, and the influence their travels there had, not only on the religion, but the art of Ireland. They might discover whether St. Columban, when King Agilulf sheltered him at Pavia, took from the artists then at work at the wondrous front of S. Michele, any ideas which he caused to be reproduced in the crosses placed by him to sanctify the open-air worship of his Irish converts; or whether he took a few monkish Magistri skilled in sculpture from his monastery at Bobbio to carve those very crosses, and to build the first stone churches, that now lie in ruins at the feet of the rugged old towers.