I noted a number of artistic motifs among the gravestones at Clonmacnois, and I recorded whether they were "present" or "absent."
Please note that some other elements were also recorded but not in large numbers.
Allow me to explain the distinction between the elements "ring" and "ringed cross motif." A "ringed cross motif" describes the presence of a ringed cross carved onto the surface of a stone, whereas a "ring" denotes that a ring has been carved out of the stone itself.
Some of these attributes cannot possibly exist on certain gravestones. For example, a recumbent gravestone (laying down rather than standing up) cannot conceivably have a "base" or a "stepped base." Meanwhile, some recumbent stones have rings and even roofs or capstones.
The "IHS motif," the "radial motif," and the "ringed cross motif" are three elements often occurring together. These three elements characterize the modern gravestones (of the past few centuries), and all of the other elements can be seen throughout the entire 1400-year sequence.
The "IHS motif" is simply the letters "IHS," often super-imposed on each other to assume the form of a single icon or emblem. "IHS" is an abbreviation for "in hocs sign," which is in turn the abbreviated version of "in hocs sign vinces." This phrase is in Latin, translated to mean "in this sign, thou shalt conquer." Other accounts identify "IHS" as representing the words "In His Service." Yet another important note is that it might represent the first three letters of the name "Jesus" in the Greek alphabet. What was the significance of the "IHS" insignia for the Clonmacnois gravestones, and why is it so closely associated with the motifs of a radial display and a ringed cross?
The phrase "in hocs sign vinces" (or "in this sign, thou shalt conquer") is traced back to AD 312. Constantine reportedly saw this phrase in the sky along with a cross of light over the sun. So the "sign" is "a cross over the sun." In this case, the "cross" may more accurately be called a "Chi-Rho emblem," associated with the development of the Christian "cross" cult. Immediately after this spiritual encounter, Constantine met great success at the Battle at the Milvian Bridge. This event marked Constantine's complete conversion to Christianity.
During his post-war celebrations, Constantine ordered the Chi-Rho monogram to be placed on his battle standard and decorated with a victor's laurel wreath. The result was reportedly a replica of what Constantine saw in his vision, and it is thought to be the protoype of the ringed cross. Click here to see a reconstruction of Constantine's famous battle standard.
The "radial" motif associated with the "IHS" motif sometimes explicitly depicts the sun's rays, emanating out from the "IHS" insignia. In other instances, the representation of the sun's radiance is not as obvious. In any case, though, the "radial" motif (just like the "IHS" motif) can be traced to the Constantine legend. The same can be said for the "ringed cross" motif (as well as for the high cross itself).
The Constantine story explains the origins of the ringed cross, but it does not explain why the ringed cross gained such prevalence in Ireland. The ringed cross also was popular in Scotland, perhaps for similar reasons. Christianity was brought to both of these places around the same time and via the same methods. Also, both Ireland and Scotland shared a common Celtic culture prior to Christianity.
The Constantine story is an example of the triumph of the Christian faith, thought to appeal to the pagan Celtic people's taste for folklore relating to magic and warfare. The Constantine story would therefore have been an important part of a Christian missionary's repertoire when converting the Irish people to the Christian religion. Under these circumstances, the ringed cross and the IHS motif understandably became key elements in Irish Christian art. The same case can be made for Scotland.
Although this story about Constantine and the "IHS" insignia may sound convincing, it must be considered critically. Certainly, other viewpoints exist. For example, origins of the "IHS" symbol might be traced to the fact that these letters are the first three letters of the name "Jesus" in the Greek alphabet. Whatever perspective is adopted to explain the origins of the "IHS" insignia, the plausibility of the story must be examined, and also the likelihood of this explanation rather than others must be considered. At present, no single perspective can be proven correct beyond reasonable doubt.
The "ringed" aspect of the Celtic cross has been interpreted in a number of ways. One interpretation deserving some attention refers to the ring as a symbol of cyclical time or unity. The four points where the cross meets with the circle represent significant points in time on a repeated time cycle such as: (a) sunrise, noon, sunset, and midnight; (b) the seasonal equinoxes and solstices; and/or (c) the four traditional Celtic seasonal festivals of Beltaine (May 1), Lugnasadh (August 1), Samhain (November 1), and Imbolc (February 1). This interpretation is attractive because of the prominence of time cycles and solar symbols in Celtic mythology. Furthermore, the Celtic cross and its associated artworks seem to relate to the sun or to solar symbols. The addition of a cross to a ring may be seen as the merging of two ideologies.
Aside from the ringed cross itslef and the IHS-related motifs, other elements of the Celtic high cross deserve attention. Nonetheless, their explanations are less detailed. Click here to see a diagram of the elements of a high cross.
"Roofs" (and to a lesser extent "capstones") have been interpreted as a reference to gravestones as "houses" for the dead. Unfortunately, little other material evidence suggests that these structures were perceived as "houses."
A "boss" is sometimes classified as a "skeuomorph," meaning that it artistically represents something whose utilitarian function has been lost in its present structural form. In this case, the "boss" element represents the head of a nail which would be necessary if the cross were made of wood. Reportedly, ringed crosses were commonly made of wood in the past, although none of them have survived archaeologically. Wood does not preserve well, especially after many centuries. Decorated nail heads added artistic value to a functional aspect of a wooden ringed cross. This form was retained stylistically with stone crosses, despite the loss of the functional value.
A "base" or a "stepped base" serves a very practical functional purpose to support the large gravestone. A possible interpretation is that a "stepped base" refers to the steps at the entrance to a house, further likening high crosses to houses for the dead. However, this interpretation lacks any foundation (pardon the pun). In fact, a "base" serves a much more practical utilitarian function.
