How Saint Patrick explained the holy trinity
It's a symbol of Ireland known all over the world, but many people may not know why the shamrock has come to be associated with Ireland.
Loved by the Irish and Irish diaspora, as well as anyone celebrating Saint Patrick's Day, the shamrock is a symbol of Ireland, worn on clothes and seen on objects.
Not to be confused with a lucky four leaf clover, the shamrock has three leaves - which are key to the reason that the shamrock is now a symbol of Ireland.
Saint Patrick is now known as the patron saint of Ireland, but he in fact was not Irish. He was born somewhere in Roman Britain, but scholars are divided as to where. He lived in the fifth century, and arrived in Ireland as a slave having been captured by pirates.
He was captive for six years, during which he converted to Christianity. He eventually left Ireland, studying further in Britain and France. He eventually returned to Ireland as a missionary, wishing to convert and baptise the pagan Irish to Christianity.
It is said that, as part of his missionary work, Saint Patrick used a shamrock.
Explaining the Holy Trinity - where God, Jesus and the Holy Spirt are three persons in one god - Saint Patrick used the shamrock as a metaphor - which has three leaves in one leaf.
The shamrock is a type of clover, although botanists and the public are divided on which species of clover exactly is a shamrock. None of these species are unique to Ireland - they all grow across Europe.
The word shamrock derives from the Irish seamróg, which is a diminutive of seamair óg meaning "young clover".
Ireland's association with the shamrock grew from the 18th century onwards, in a similar way to other associations like a rose for England, a thistle for Scotland and a daffodil for Wales.
Shamrocks, in particular, have been celebrated in traditional Irish music.
So the next time you see a bunch of shamrocks on Saint Patrick's Day, you'll now know where the tradition comes from.