DUBLIN — He downed a pint of Guinness with a distant cousin and checked out centuries-old parish records tracing his family to Ireland. From the tiny village of Moneygall to a huge, cheering crowd in Dublin, President Barack Obama opened his four-nation trip through Europe on Monday with an unlikely homecoming far removed from the grinding politics of Washington and the world.
"My name is Barack Obama, of the Moneygall Obamas, and I've come home to find the apostrophe we lost somewhere along the way," a clearly tickled Obama — make that O'Bama — told the overflow throng at Dublin's College Green with his wife, Michelle, right by him. "We feel very much at home."
Obama's feel-good indulgence in Ireland came at the start of a four-country, six-day trip that is bound to get into stickier matters as he goes. The only hitch on day one was the threat of a volcanic ash cloud from Iceland that led the president to leave Ireland without even a night's stay and land in England on Monday night.
His high point in Ireland was a helicopter jaunt to Moneygall, population 350 give or take it, where the president's great-great-great grandfather, Falmouth Kearney, was born and where thousands congregated to welcome the United States' first black president home. Obama met there with his nearest Irish relative, 26-year-old accountant Henry Healy, and they stopped in at Ollie's Bar for a Guinness.
Video: Irish village embraces Obama (on this page)
It was a moment and a pint to savor. To the approval of the pub crowd and people all across Ireland watching on television, Obama downed the full pint in four slurps and came away with a foam mustache.
"The president actually killed his pint! He gets my vote," said Christy O'Sullivan, an Irish government clerical worker taking a long lunch break to watch live TV footage of Obama's visit. "He's the first president I've actually seen drink the black stuff like he's not ashamed of something."
An Irish link is good news for any American politician trying to connect with voters, and particularly for one who's been dogged by questions about whether he was even born in the United States. By some estimates, 35-40 million Americans trace their ancestry to Ireland. While Ireland, population 4.5 million, is a relatively small player on the world stage, this nation roughly the size of West Virginia has been a popular stopping point for modern American presidents ever since John F. Kennedy came in 1963.
For Obama, it was a day reminiscent of the campaign season when candidate Obama was greeted by adoring crowds and the president milked it for all it was worth. He spoke enthusiastically Monday of "the bonds of affection" between the United States and Ireland. "There's always been a little green behind the red, white and blue," he said to cheers in Dublin.
It wasn't until the 2008 presidential campaign that Obama discovered he had Irish roots, when a priest of the local Anglican church, Canon Stephen Neill, located the family's baptismal records and established the connection. Falmouth Kearney, who immigrated to the United States in 1850 at the age of 19, is a great-grandfather of Obama on his Kansas-born mother's side. His father was born in Kenya.
Video: President Obama charms Ireland (on this page)
In Moneygall, 14-year-old Grainne Ryan scrawled "Obama" and drew a shamrock on her cheeks with eyeliner. Thirty-one-year-old Tara Morris pronounced herself "star-struck," a sentiment that appeared to be shared by many in a country that could use a boost as it weathers a steep economic downturn after its boom years as the Celtic Tiger.
Michelle Obama, for her part, drank her full half-pint and then got behind the bar herself to serve Moneygall's parish priest, the Rev. Joe Kennedy.
The president said the brew somehow tasted better in Ireland than in America. And, by the same token, the crowds here were by far more enthusiastic than those greeting him back home of late.
After getting to London a night earlier than scheduled and overnighting at the U.S. ambassador's residence, the Obamas will enjoy the rarified pomp of a state dinner and sleepover at Buckingham Palace, with Queen Elizabeth II as host.
But Obama also will confront difficult problems as he moves on to England and then France and Poland.
In advance of his arrival in London, Obama announced the formation of a new joint U.S.-British national security council designed to allow the two countries to work more closely together and share intelligence on long-term security challenges, particularly in the Middle East and Afghanistan.
British Prime Minster David Cameron said there were plenty of challenges to discuss.
"We've got some proper, very long talks, discussions about Libya, Afghanistan, security issues and also prosperity," Cameron told Britain's ITV. "The other big concern Barack and I have is making sure there are more jobs for our people, so getting trade going, making sure the economy's moving, dealing with our debts and deficits."
In Ireland, Obama said the success of the Northern Ireland peace agreement "speaks to the possibility of peace" in other world trouble spots.
His journey began with an overnight flight from Washington aboard Air Force One. The president and first lady met Ireland's President Mary McAleese at her official residence, and Obama participated in a tree planting ceremony as children rang a peace bell marking the 10th anniversary of the Good Friday accord.
Obama then met the prime minister, Enda Kenny, and told him: "For the United States, Ireland carries a blood link with us."
Thousands of people waited hours to hear Obama speak in Dublin, and many more were turned away as the scene neared dangerously overflow conditions. The president sought to endear himself to the locals by speaking some phrases in Gaelic, including his campaign slogan of "Yes we can."
After his time in England, Obama will travel to Deauville, France, to meet with the heads of leading industrial nations, before ending his Europe trip with a visit to Poland, a strategically important Central European ally.
Reuters and The Associated Press contributed to this report.