A Celtic cross (Irish: cros Cheilteach) is a symbol that combines a cross with a ring surrounding the intersection. The early Celtic stone high cross is generally in the form of a normal cross with a ring joining the arms for structural strength, often with an extended rectangular or cubic base that is mounted on the ground. Early groups have broad undecorated front faces with many animal scenes in relief.
Later groups have narratives upon them. In Ireland, it is a popular myth that the Celtic Christian cross was introduced by Saint Patrick or possibly Saint Declan during his time converting the pagan Irish. It is believed that Saint Patrick combined the symbol of Christianity with the sun cross, to give pagan followers an idea of the importance of the cross by linking it with the idea of the life-giving properties of the sun.
In Celtic regions of Ireland and later in Great Britain, many free-standing upright crosses (or high crosses) were erected by Irish monks, beginning at least as early as the 7th century. Some of these 'Celtic' crosses bear inscriptions in runes. There are surviving free-standing crosses in Cornwall (famously St Piran's cross at Perranporth) and Wales, on the island of Iona and in the Hebrides, as well as the many in Ireland.
Other stone crosses are found in the former Northumbria and Scotland, and further south in England, where they merge with the similar Anglo-Saxon cross making tradition, in the Ruthwell Cross for example.