Who was St. Patrick and what did he do?

He was born between 387 and 390 at Scotland as Maewyn Succat and died between 461 and 464 at Saul, County Down, Ireland of natural causes.
St. Patrick was actually a missionary in Ireland that spent his later life converting druids over to Christianity, from Paganism.

He started over 300 churches and used the 3 leafed clover to teach others about the Holy Trinity.
St. Patrick is largely responsible for converting Ireland to Christianity.
as a child he lived with a weathy family he was kidnapped and had to work as a Shepard when he grew up he traveled far and died on the 17 that's why we celepbrate st Patrick day