When Ireland was still a land of the Druids, St. Patrick came to teach of the one God. Legend suggests that St. Patrick used a Celtic shamrock to demonstrate the meaning of the Christian trinity (Father, Son, and Holy Ghost). Although one myth states that St. Patrick inspired this (in a Christian view), earlier legends suggest that the trinity has long been part of the Irish culture. The Celtic shamrocks are renowned for having mystical power and meaning. It's petals will stand upright to warn of an approaching storm. Even today the shamrock is Ireland's most famous symbol. The Celtic shamrock is the unofficial symbol for Ireland.

To the druids, the Celtic shamrock was, and is, a sacred plant because its leaves form a triad. Three is a mystical number in the Celtic religion. In ancient days of the Christian inquisition, the shamrock was a sign of rebellion. Anyone wearing a shamrock was hanged. It was also a sign of rebellion by the Irish to the English in those days.

The Celtic shamrock design is used in Irish pubs around the world as a sign of an English speaking, warm establishment.

The beautiful Celtic Shamrock is a plant with three leaves. A symbol based on the clover. Its name comes from the Irish “seamrog”, a shorter version of sea mar clover. The early Druids revered the plant as sacred. It grows with such vitality that it came to represent life itself. In medieval love poetry, this theme continued with stories of young couples who would meet or make love in clover.

The phrase "in clover" originated from the shamrock and came from livestock grazing off  Celtic clover.

Although the interesting heritage of the shamrock undoubtedly contributes to a beautiful symbolic meaning, Clover was often planted on graves to symbolize the hope of new life, thus by association, also symbolizes a sense of parting. Today, the shamrock is not just a symbol, it is the unofficial the symbol of Ireland itself.

In Celtic tattoos, a Shamrock image is often paired with other symbols of Ireland, including harps, leprechauns, or even the early name of Ireland itself “Erin”. Every year the Emerald Isle ships great quantities of shamrocks to other countries. They export them to help others celebrate St. Patrick’s Day, a patron saint. Not just for that, but also for its long history as an important symbol of the sacred heritage of the Irish.