An Irish blessing was bestowed upon the world Saturday in honor of St. Patrick's Day 2012. Celebrations of green-clad revelers took place around the world.

In New York City, the annual St. Patrick's Day parade glided down Manhattan's Fifth Avenue. Mayor Michael Bloomberg walked in the 251st annual parade, waving the Irish tricolor and greeting revelers. 

It's a wonderful day to be Irish, a great day to celebrate, Bloomberg told the New York Daily News just before marching up Fifth Avenue. Forty percent of people who live in New York City are from outside America, and that's one of the great strengths of New York City.

Cardinal Timothy Dolan greeted the mayor outside St. Patrick's Cathedral. Now in New York, St. Patrick's Day is so wonderful because it brings everybody together, which is what the Irish are all about, Dolan told The New York Daily News. They're all around the world, and they just bring people together in love and service.

In Washington, the fountain on the South Lawn of the White House flowed with bubbling green water, and President Barack Obama celebrated with a pint of Guinness at the Dubliner Irish Pub in Washington. 

In Aldershot, England, the Duchess of Cambridge, Kate Middleton, presented shamrocks to members of the 1st Battalion Irish Guards at Aldershot Barracks. A parade was held as well. Middleton wore a teal pleated coat, a brown hat and shamrocks on her lapel. 

Surely, the most popular of Irish blessings was shared on St. Patrick's Day amongst celebrators: 

May the road rise up to meet you.
May the wind always be at your back.
May the sun shine warm upon your face,
and rains fall soft upon your fields.
And until we meet again,
May God hold you in the palm of His hand. 

Here are photos of St. Patrick's Day 2012 celebrations around the world on Saturday, March 17.