Saint Patrick's Day is a cultural and religious holiday observed annually on March 17. It commemorates Saint Patrick, the foremost patron saint of Ireland, and marks the traditional date of his death in the fifth century. Originally established as a Christian feast day, the observance has evolved into a global celebration of Irish culture and heritage, recognized both within and far beyond the Irish diaspora.
The historical figure of Saint Patrick was a Romano-British missionary who is credited with bringing Christianity to Ireland. Associated traditions and symbols are central to the holiday's identity. The shamrock, a three-leafed plant, is linked to the legend of Patrick using it to explain the concept of the Holy Trinity. The color green became widely associated with the day starting in the 18th century, supplanting the earlier use of blue, due to its connection to the shamrock and Irish nationalist movements. While it began as a solemn religious observance in Ireland, the large-scale public parades and festivities now characteristic of the day were first developed by Irish emigrant communities in North America.
Modern observance of the holiday encompasses a range of activities that vary by region. It is a public holiday in the Republic of Ireland, Northern Ireland, the Canadian province of Newfoundland and Labrador, and the British Overseas Territory of Montserrat. Celebrations typically involve public parades, festivals known as cilithe, the wearing of green attire or shamrocks, and the temporary lifting of Lenten restrictions on food and alcohol consumption. This has cemented its status as both a significant liturgical date for various Christian denominations and a prominent secular festival celebrating Irish identity worldwide.
