To many, St. Patrick's Day means green beer and rousing choruses of "When Irish Eyes Are Smiling'' but the real legend is far less whimsical.

St. Patrick was born 390 A.C. of Romano and British parentage in Scotland, reportedly in an area called Dumborton, in the west of Scotland.

According to legend, he was captured at the age of 16 by Irish raiders while tending flocks and taken to Ireland where he was sold into slavery.

While enslaved, St. Patrick became a Christian.

After six years in captivity he managed to escape and studied in France where he later became ordained.

St. Patrick returned to Ireland in 432 A.C. to spread the gospel. He travelled around the country organising the scattered Christian communities which he found in the north.

And he founded the archepiscopal of Armagh, a county in northern Ireland, in 444 A.C. which became the centre of Christianity in Ireland.

St. Patrick also became the first bishop of Armagh.

Reportedly in his old age, St. Patrick climbed to the top of Mount Aigli and remained there for 40 days and 40 nights.

Historically saints are divided into two groups, one comprising true stories of exceptional human beings like St. Joan of Arc.

The second group consists of legendary characters who inspired adventure stories like St. Christopher -- the patron saint of travellers.

According to legend, St. Patrick rid the Emerald Isle of snakes and as a result he is often portrayed crushing a serpent beneath his heel.

St. Patrick, who reportedly died in 461 A.C., was also responsible for the shamrock becoming Ireland's national plant.

He used the shamrock to describe the mysteries of Christianity. The three branches of the plant were used to describe the Trinity -- the Father, the Son and the Holy Ghost.