Where it all began...
St Patricks Day, or the Feast of St Patrick, is held on the 17th of March every year, on the known death day of the most famous patron saint of Ireland; Saint Patrick.
Back in the 5th century, Patrick was captured as a young boy of 16 and brought to Ireland as a slave, to look after sheep. After just six years, he escaped home and became a Priest, where he had a dream that God spoke to him and told him that the people of Ireland needed him to return to teach them about Christianity. Patrick agreed and returned to Ireland once more to convert the Irish people from Paganism to Christianity.
It was from here that he was said to have used a Shamrock with three leaves to explain the Holy Trinity to the Irish people, which is why it is so prominent in todays Irish celebrations. He was also said to have banished all the 'snakes' or 'evil spirits' from the island for the Irish people.
Patrick became a Bishop during his time in Ireland, and when he died, they made him the patron saint. St Patricks Day became a massive celebration after Irish people started immigrating to America and celebrating St Patricks Day was a good way for them to connect back to their Irish roots after they had moved away from the Island. The first ever Saint Patricks Day Parade was held in Boston in 1737.
Wearing green during St Patricks Day also didn't come about until 1798; when the Irish soldiers were fighting the British during the Irish Rebellion, they wore green. The colour Green was then linked to the Shamrock, and it forever became the colour that we wear to celebrate St Patricks Day today.