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Legend of the shamrock. St Patrick. The Irish shamrock symbol is closely associated with St Patrick, the patron saint of Ireland. St Patrick is believed to have been from Scotland or Wales. Irish raiders captured and enslaved him at the end of 4th Century. He spent six years in slavery, probably in the West of Ireland.
The basic Celtic Cross is a symbol comprising a conventional cross with a ring around the intersection of the stem and the arms (as per the more elaborate example above). more Christian theory is that the ring is a halo and that the cross represents Jesus Christ. It is also thought that the Christian monks combined the sun-god idea with the christian cross to broaden the appeal to Irish pagans.