 The most significant survivals in sculpture are in High crosses , large free @-@ standing stone crosses , usually carved in relief with patterns , biblical iconography and occasionally inscriptions . The tradition may have begun in Ireland or Anglo @-@ Saxon England and then spread to Scotland . They are found throughout the British Isles and often feature a stone ring around the intersection , forming a Celtic cross , apparently an innovation of Celtic Christianity , that may have begun at Iona . Distribution in Scotland is heaviest in the Highlands and Islands and they can be dated to the period c . 750 to 1150 . All the surviving crosses are of stone , but there are indications that large numbers of wooden crosses may also have existed . In Scotland biblical iconography is less common than in Ireland , but the subject of King David is relatively frequently depicted . In the east the influence of Pictish sculpture can be seen , in areas of Viking occupation and settlement , crosses for the tenth to the twelfth centuries have distinctive Scandinavian patterns , often mixed with native styles . Important examples dated to the eighth century include St Martin 's Cross on Iona , the <unk> Cross from the Hebrides and the Anglo @-@ Saxon <unk> Cross . Through the Hiberno @-@ Scottish mission to the continent , insular art was highly influential on subsequent European Medieval art , especially the decorative elements of Romanesque and Gothic styles . 
