Being Ireland’s ambassador to the United States is like being a rock star: Everyone loves your work, even if they only know your greatest hits.

Michael Collins — the latest of a long string of popular Irish ambassadors, and the longest-serving one in decades — is making his farewell lap this summer, as he and wife Marie bid farewell with a final round of parties after six years in Washington.

Last week it was an homage to James Joyce’s “Ulysses,” the annual celebration of Bloomsday. “It is the only book that has a day every year dedicated to it which is enjoyed by so many people around the world — even if they haven’t actually read “Ulysses,” he told the crowd at the embassy’s residence in Kalorama.

Bloomsday, Guinness, St. Patrick’s Day — such beloved cultural exports are part of Collin’s diplomatic portfolio. “We have an extraordinary manifestation and outburst of affection for Ireland,” he told us. “Not just the Irish, not just the Irish-Americans, but seemingly everybody else enjoys sharing our day with us.”

The upside? More than 40 million Americans trace their ancestry to Ireland, which means a St. Patrick’s party every year at the White House and easy entree to many U.S. powerbrokers. An invitation to the embassy is one of the most popular in D.C., in part due to the tasty liquid exports. (“We don’t feel an obligation” to serve Irish booze, Collins said. But “they happen to be the best. People expect that, and we don’t like to disappoint them.”)

The downside? Trying to convey to Americans the current-day realities of his country as part of the European Union. “We have to articulate a sense of Ireland today — its modernity, its issues, its challenges, its opportunity, its culture,” said Collins. “That’s what we do the rest of the year.”

The career diplomat arrived in D.C. in 2007 and is gratified by the sustained peace in Ireland and Northern Ireland since that time. “To be here in the United States in these years and to be able to say, ‘Ireland is a country at peace.’ That is really something I’m just so proud of. . . it means so much, obviously for us at home, but it means an awful lot to people here as well.”

It’s a busy few weeks ahead: Collins flew to Dublin Sunday for the Obamas’ visit and the 50th anniversary of JFK’s historic trip to Ireland. Then it’s back to D.C. for a series of goodbyes, which he and his wife managed to fend off until this month.

“Obviously, we understand in our business that you have to move on,” he said, “but after six years, you’re in pretty deep.” They plan a grand finale in the middle of July.

In August, Collins heads to Berlin, and his successor will make history of her own: Anne Anderson, now Ireland’s representative to the U.N., will be its first female ambassador to the U.S.