widely used in neighbouring Roman Britannia, while runes in the 4th century were not very widespread even in continental Europe. In Ireland and in Wales, the language of the monumental stone inscriptions is termed Primitive Irish. The transition to Old Irish, the language of the earliest sources in the Latin alphabet, takes place in about the 6th century. Since ogham inscriptions consist almost exclusively of personal names and marks possibly indicating land ownership, linguistic information that may be glimpsed from the Primitive Irish period is mostly restricted to phonological developments. Theories of origin There are two main schools of thought among scholars as to the motivation for the creation of ogham. Scholars such as Carney and MacNeill have suggested that ogham was first created as a cryptic alphabet, designed by the Irish so as not to be understood by those with a knowledge of the Latin alphabet. In this school of thought, it is asserted that "the alphabet was created by Irish scholars or druids for political, military or religious reasons to provide a secret means of communication in opposition to the authorities of Roman Britain." The Roman Empire, which then ruled over neighbouring southern Britain, represented a very real threat of invasion to Ireland, which may have acted as a spur to the creation of the alphabet. Alternatively, in later centuries when the threat of invasion had receded and the Irish were themselves invading the western parts of Britain, the desire to keep communications secret from Romans or Romanised Britons would still have provided an incentive. With bilingual ogham and Latin inscriptions in Wales, however, one would suppose that the ogham could easily be decoded by at least an educated few in the Post-Roman world. The second main school of thought, put forward by scholars such as McManus, is that ogham was invented by the first Christian communities in early Ireland, out of a desire to have a unique alphabet for writing short messages and inscriptions in the Irish language. The argument is that the sounds of Primitive Irish were regarded as difficult to transcribe into the Latin alphabet, so the invention of a separate alphabet was deemed appropriate. A possible such origin, as suggested by McManus (1991:41), is the early Christian community known to have existed in Ireland from around AD 400 at the latest, the existence of which is attested by the mission of Palladius by Pope