The Celtic cross is a symbol widely associated with Ireland, but many may not know the unique history and debate surrounding this unique and instantly recognizable symbol. The Celtic cross combines a cross with a circle surrounding its intersection, but other than that description, little can be confirmed about the origins of this symbol that some historians believe can be traced back to ancient paganism. Historical revisionist author and researcher Crichton E.M. Miller theorizes that the cross had more practical purposes than those subscribed to it today, serving as a navigational device used by ancient explorers and builders. One popular, though highly unlikely, theory regarding the origins of the Celtic cross is that it was introduced by St. Patrick, Ireland's patron saint. This theory states that St. Patrick, or possibly St. Declan, combined the cross, which is the foremost symbol of Christianity, with the sun cross, a circular symbol traced to prehistoric cultures, in an attempt to illustrate the importance of the cross to the pagans he was attempting to convert. Though the exact origins of the Celtic cross and its meaning will likely never be known, there is no denying its endurance as a symbol and its ongoing association with Ireland.