Nearly 200 carved crosses have survived on the Isle of Man dating from the early Celtic Christian period in the 7th century and through the period of the Viking settlement, up to the early Eleventh century. The interlinked ring design forming the shaft is of Scandinavian (Viking) influence. The wheel cross at the top of the cross was originally a symbol of Christ, derived from the Chi-rho monogram, although it is likely that the outer circle came to symbolize heaven (in conformance with ancient symbolism) and the center of the cross, Christ in the center of heaven, represented by the inner circle.