It seems that Irish American comics are taking over the late night airwaves in the US. First Conan O’Brien, who hosts “Conan” on TBS, then Jimmy Fallon, who recently took over from Jay Leno as the presenter of “The Tonight Show,” and now Stephen Colbert is to become part of late night royalty.

The Irish American comedian and host of Comedy Central’s “Colbert Report” will replace David Letterman as the house of CBS’s “Late Show” next year.

The network announced, on Thursday, that Colbert will sign a five-year deal to replace Letterman when he retires.

In a statement released by the network Colbert said, “Simply being a guest on David Letterman’s show has been a highlight of my career.

“I never dreamed that I would follow in his footsteps, though everyone in late night follows Dave’s lead.”

He added, “I’m thrilled and grateful that CBS chose me. Now, if you’ll excuse me, I have to go grind a gap in my front teeth.”

Colbert a proud Irish American recently had his Irish roots dissected by Henry Louis Gates on the PBS documentary series “Faces of America.” Colbert has spoken of his Irish roots many times in the past, and takes part in New York Bloomsday celebrations, in honor of the James Joyce classic "Ulysses."

On the show Colbert and Gates talked about the effect of British colonialism in Ireland, with Colbert saying that the Irish in America will never forget the British driving their ancestors off their land.

“Part of being Irish even to this day is not liking the English,” said Colbert with a laugh. “Absolutely no doubt.”

The comic recalled being scared to tell his mother about his future sister-in-law’s accommodations in New York. No, she wasn’t living in sin. It was actually worse. She was residing at a building on 72nd Street called the Oliver Cromwell.

“I thought, I can’t tell my mom that!,” said Colbert. “Cromwell is like Satan. He drove our family west of the River Shannon to farm rocks 350 years ago! I was raised on that story.” (Cromwell, of course, was the British tyrant who slaughtered scores of Irish back in the 1600s.)

After Colbert and his wife Evelyn McGee married he did a roots search on her background and, horror of horror, he discovered that her Irish ancestors were from Co. Tyrone in Northern Ireland, “on land that had been given to them by the Crown,” Colbert told Gates.

“I said to her, ‘Your family got my family’s land!” he joked. “But that’s what’s fantastic about America – 300 years later we get married.”

Researchers for the Gates show contacted a Dublin historian, who then reached out to Limerick genealogist Tony Browne, who helped unearth Colbert’s great-great grandfather, a native of St. Mary’s parish in Limerick city.

“(They) got in touch with me and asked me to track down a Michael Gearon or Guerin in Limerick. I got on to Father Donough O'Malley and we were able to find him on the parish register," Browne told the Limerick Leader newspaper.

Browne discovered a marriage entry of a Michael Gearon to Johanna Nicholson in January of 1834. The couple had three children and eventually went to America, but Browne said poor recordkeeping at the time prevented them from discovering when the Gearon family departed.

"I'll have to wait to watch the program to see if they found out what happened, but my guess is that they might have ended up in Canada and walked across the border as you could do back then. Stephen Colbert grew up in Carolina," said Browne.

Check out this PBS clip where Colbert discussing searching his family's roots: