John Hannegan and his wife, Patty, who with Chris Benson share ownership of C.B. Hannegan's, an Irish pub and restaurant in Los Gatos, have developed a wide network of friends over the years who work in San Jose and the Silicon Valley. But many of them reside in Los Gatos and come from Irish backgrounds. Over the years, since around 1986, those friendships and connections have also branched overseas to Ireland.

Hannegan said San Jose has a long-standing sister-city relationship with Dublin, Ireland, and more recently with the city of Derry in Northern Ireland. Representatives from both cities paid a visit to C.B. Hannegan's during a March 10 trip to the South Bay.

"It started as a small seed in 1986, and it has grown from a group of hundreds of people to thousands," said Hannegan, in terms of different Irish groups sprouting in the Silicon Valley. "C.B. Hannegan's is one branch in a big tree."

The purpose of elected officials from Dublin and San Jose developing a sister-city relationship is to exchange educational, environmental and cultural programs as well as business opportunities, Hannegan said, adding that they are using each other and their resources wisely.

Kevin Dowling, Dublin's executive manager, said Dublin and San Jose are of comparable sizes in population. Dublin is becoming more involved in the high-tech industry as well. The city has three universities, including University of Dublin Trinity College.

And because of Hannegan's Irish connections—even though he's a native Californian with Irish heritage—the sister-city friendship has spread to Los Gatos.

Lord Mayor Councillor Royston Brady of Dublin and Mayor Councillor Shaun Gallagher of Derry and his wife, Mayoress Majella Gallagher of Derry, were among many who celebrated the sister-city relationship at C.B. Hannegan's March 10. To make the guests feel welcome, C.B. Hannegan's featured traditional Celtic and bluegrass musicians on hammered dulcimers, banjos, fiddles and pipes, as well as plenty of food and Guinness by the pint. Los Gatos Mayor Steve Glickman played along during the "jam session" on a drum.

"I'm just very proud that there are so many cultural heritages here that have the opportunity to express themselves," Glickman said.

Gallagher said he and his wife had previously toured Boston and Seattle before coming to San Jose. As for what he thought of Los Gatos, Gallagher said it was delightful and the Celtic music was hospitable.

"It's just lovely. The people here are very, very friendly, and my wife has enjoyed the shopping," said Gallagher, with a thick Irish accent.

In Ireland, Majella Gallagher said, St. Pat's Day—a national holiday—is a one-day-only celebration, unlike the weeklong extended celebrations she experienced during her stay in America.

"There are parades and festivals and music in the streets—like Mardi Gras," she said. "But we don't have green beer."

Brady, who had just stepped off the plane before coming to C.B. Hannegan's, said his visit would be shorter than the Gallaghers', since he had to get back to Dublin for the March 17 parade.

After both mayors were greeted publicly by Glickman, Brady offered his appreciation for the invitation and thanks to Hannegan and to Ray O'Flaherty, president of the All Ireland­U.S. Chamber of Commerce and past president of the Dublin­San Jose sister-city program, who helped foster the mutual friendship.

"It's an honor to be here. We are extremely excited," Brady said. "We've been twinned for over 16 years now. It's one of the longest ones we've been associated with, and we're going to do our part to keep it going."