One of the best-known British authors reported his hopes for a united Ireland and said the move was overdue for hundreds of years.
Jack Reacher author Lee Child, whose crime books have been made into films with Tom Cruise, said the reunification of the island could be a positive outcome of Brexit.
The Coventry-born child, whose father was from Belfast, is currently applying for an Irish passport and said he would vote on any upcoming referendum if he could.
When he picked up a gong at Buckingham Palace on Friday, he told the PA news agency: "I make no difference between north and south and really hope that the island will soon be united.
"I hope that will be the positive result of Brexit. It is hundreds of years past due."
He added: "I think Brexit will make people think about it as a viable option and maybe a necessary option, and I think it would be a positive step."
Child, who has collected a CBE for literary services, said the atmosphere is now right for people to have a say in the question of unity.
He said: "When I was a little kid, the hostility was enormous, but now I think everyone feels much better."
When asked how he had seen Sinn Féin's rise in the republic, he said he believed it was now a different party from the one that has sparked controversy over the years over its historical ties to the Provisional IRA.
He said: "Sinn Féin had a terrible reputation 40 and 50 years ago, but I think we have to say that's the past, let's look to the future."
Elvis Costello, real name Declan McManus, with his OBE for music services after a furnishing ceremony at Buckingham Palace, London. Picture by Victoria Jones / PA Wire
Elvis Costello, who also received an honor at today's ceremony, described a united Ireland as "inevitable".
"United Ireland, I think, is inevitable. Maybe in my life, in my children's lives," he said after he was named OBE for music services.
"The most important thing is that there will be peace, that there will be no recourse to violent means to resolve this, because it clearly did not help us."
Costello, who described his late father as a nonviolent Irish Republican, suggested that the current political climate could lead other countries to break away from Britain and form a "Celtic Union".
"Everyone seems to want to belong to something different than before," said the singer, who was born Declan MacManus and whose family comes from Co Tyrone.
He added with a smile: "Maybe there will be a Celtic Union, maybe Scotland will leave the Union and unite with Ireland. Why not? There is a good idea."
(tagsToTranslate) United Ireland (t) Lee Child (t) Elvis Costello