More than half a million people have packed Dublin city centre as the annual St Patrick's Day parade got under way.
Every man, woman and child - whether from Tralee or Timbuktu - could call themselves Irish for the day as they soaked up the sights and sounds of the nation's favourite holiday.
"What other country can bring people from all around the world to celebrate its own culture?" said Stephanie Reimer, from Canada. She and a group of friends, dressed from head to toe in green, had the best view of the two-hour parade where it snaked across the River Liffey on the O'Connell Bridge.
"What I love about St Patrick's Day is that it's an inclusive celebration that invites absolutely everyone and allows us all to be Irish for a little while," she added.
The parade set off from Parnell Square, along O'Connell Street, past Trinity College and concluded at St Patrick's Cathedral. To mark Dublin's year as the City of Science, the parade theme was How? What? Why?
Street performers and theatre companies gave extravagant displays of colour and dance, portraying different scientific concepts from questions posed by Irish schoolchildren. One troupe had dancers dressed as raindrops and different colours, as it tried to illustrate how a rainbow is made while another group, which answered the question of why we dream, danced behind a giant nightmarish dragon, a metallic rhinoceros and 20ft (6m) tall flowers.
Dublin man Rory Larkin said it is the colours, sounds and electric atmosphere that attract him and his family each year. "It makes you proud to be Irish," said Mr Larkin, with a tricolour-painted face and his hair dyed green.
Marching bands from Ireland, the UK, Russia and the US kept the crowds on their toes with rousing renditions of songs like It's A Long Way To Tipperary". Among them was a band from the University of Notre Dame in Indiana, which is home to the Fighting Irish football team.
The team is due to play a match against the Naval Academy at Dublin's Aviva Stadium in Lansdowne Road in September, and is expected to bring some 30,000 football fans with it from the States.
The Dublin Fire Brigade Band, Garda Band and Garda Dog Unit also took part in the spectacle, and were followed by an array of performers on stilts, bicycles and skates, throwing batons and breathing fire.