There are many modern 'politically correct' problems surrounding exactly what is Celtic and what is not. The most common error is to talk of 'Celtic knotwork', that complicated and elaborate interlacing of lines, curves and geometric shapes which seems to be appearing everywhere nowadays. This style of design and decoration was in fact brought to Britain in the 6th century AD by Saxon Christian monks and was used exclusively to illuminate the hand-written Christian Gospels. The Saxon people used some of the art for personal decoration. Any of the knotwork that has animal shapes incorporated shows influence from the Vikings. It is indeed a very attractive and distinctive style of decoration - but it is not Celtic.