The 17th of March is St Patrick's day. You might have heard a little bit about this before. Perhaps you saw the decorations at the school, or maybe you have been to an Irish pub in March. But it is likely you don't know what it's really all about.
The truth is, it is not really about anything anymore. It is nowadays just an excuse to get really drunk. But it has some interesting origins. Thousands of years ago Ireland, like much of Europe, was not christian, it was pagan (this was a religion with many gods that worshiped nature, much like Shinto). Rome however was Christian, and this meant so were its colonies, of which England was one.
St Patrick was a Romano-British Catholic priest who took Christianity to Ireland. Originally meant to celebrate the introduction of Christianity to Ireland the holiday has over the years transformed into a holiday to celebrate Ireland in general. The symbols of Ireland have become the symbols of the holiday, Shamrocks, the leprechaun, the color green and Guinness beer. Because many Irish people moved to Canada, Australia, New Zealand and the USA the holiday has become popular there also.
Most famous Irishman, not actually Irish.