According to the author of St. Patrick of Ireland: A Biography.
At 16, Patrick's world turned: He was kidnapped and sent overseas to tend sheep as a slave in the chilly, mountainous countryside of Ireland for seven years.
"It was just horrible for him," Freeman said. "But he got a religious conversion while he was there and became a very deeply believing Christian."
St. Patrick's Disembodied Voices
According to folklore, a voice came to Patrick in his dreams, telling him to escape. He found passage on a pirate ship back to Britain, where he was reunited with his family.
The voice then told him to go back to Ireland.
"He gets ordained as a priest from a bishop, and goes back and spends the rest of his life trying to convert the Irish to Christianity," Freeman said.
Patrick's work in Ireland was tough—he was constantly beaten by thugs, harassed by the Irish royalty, and admonished by his British superiors. After he died on March 17, 461, Patrick was largely forgotten.
But slowly, mythology grew around Patrick, and centuries later he was honored as the patron saint of Ireland, Freeman noted.
St. Patrick's Day Shamrock Shortage
According to St. Patrick's Day lore, Patrick used the three leaves of a shamrock to explain the Christian holy trinity: the Father, the Son, and the Holy Spirit.
Today, St. Patrick's Day revelers wear a shamrock out of tradition. But people in Ireland hoping to wear an authentic shamrock are running low on luck.
Trifolium dubium, the wild-growing, three-leaf clover that some botanists consider the official shamrock, is an annual plant that germinates in the spring. Recently, Ireland has had two harsh winters, affecting the plant's growth.
Other experts pin the shortage of the traditional plant as much on modern farming methods and loss of traditional hay meadows.
"The cold winters we are having here lately are just another nail in the coffin," a landscape and nature photographer whose books includeThe Wildflowers of Ireland, said via email.
To make up for the shortfall, many sellers are resorting to other three-leaf clovers, such as the perennials Trifolium repens and Medicago lupulina. According to the Irish Times, these plants are "bogus shamrocks."
Trinity College's Parnell agreed that Trifolium dubium is the most commonly used shamrock today, which lends credence to the claims of authenticity.
However, he added, the custom of wearing a shamrock dates back to the 17th and 18th centuries, and "I know of no evidence to say what people then used. I think the argument on authenticity is purely academic—basically I'd guess they used anything cloverlike then."
What's more, botanists say there's nothing uniquely Irish about shamrocks. Most clover species can be found throughout Europe.
No Snakes in Ireland
Another St. Patrick myth is the claim that he banished snakes from Ireland. It's true no snakes exist on the island today, Freeman said—but they never did.
Ireland, after all, is surrounded by icy ocean waters—much too cold to allow snakes to migrate from Britain or anywhere else.
Since snakes often represent evil in literature, "when Patrick drives the snakes out of Ireland, it is symbolically saying he drove the old, evil, pagan ways out of Ireland [and] brought in a new age," Freeman said.
The snake myth, the shamrock story, and other tales were likely spread by well-meaning monks centuries after St. Patrick's death, Freeman said.
"St. Patrick's Day was basically invented in America by Irish-Americans," Freeman said.
Eighteenth-century Irish soldiers fighting with the British in the U.S. Revolutionary War held the first St. Patrick's Day parades. Some soldiers, for example, marched through New York City in 1762 to reconnect with their Irish roots.
