Prince Harry has talked of how people can make a “difference” in changing society for the better, as he guest edited BBC Radio 4’s Today programme.
The programme focused on the armed forces, mental health, youth crime and climate change.
It included interviews he conducted with former US President Barack Obama and his own father, Prince Charles.
Ahead of his wedding to Meghan Markle, Prince Harry said he was determined 2018 would be a “fantastic year”.
He said: “For me, post-Christmas, at this time of year, I just hope everyone out there has had a chance to just think about the things that really matter and the difference that every single one of us can make.
“Part of my role and part of my job is to shine a spotlight on issues that need that spotlight, whether it’s people, whether it’s causes, issues, whatever it is.
“So I will continue to play my part in society.”
In the prince’s interviews, Mr Obama said irresponsible use of social media was distorting the public’s understanding of complex issues, while the Prince of Wales said climate change was causing untold horrors” in different part of the world.
At the end of the programme, presenters Justin Webb and Sarah Montague turned the microphone on the fifth in line to the throne, who spent Christmas at Sandringham with other members of the Royal Family and his fiancée Meghan Markle.
Prince Harry said he had an “amazing time” at Christmas – Ms Markle “really enjoyed it and the family really loved having her there” although there were “plenty” of family traditions he needed to explain to her.
The 33-year-old said they had a great time staying with the Duke and Duchess of Cambridge and “running around with the kids” and were really looking forward to 2018.
American actress Ms Markle’s presence at Sandringham was the first time someone yet to marry into the Royal Family has been invited to take part in their Christmas celebrations.
Prince Harry said: “She’s done an absolutely amazing job, she’s getting in there and it’s the family that I suppose she’s never had”.
‘Big learning curve’
It is the 14th year public figures have been in control of the Today’s output between Christmas and New Year.
Other guest editors this week include a robot, Bletchley Park code-breaker Baroness Trumpington, Tamara Rojo of the English National Ballet and poet and novelist Benjamin Okri.
The programme also featured an audio diary recorded by Prince Harry in Toronto at the Invictus Games, the Paralympic-style competition for injured service personnel he launched in 2014.
And he conducted an interview with British artificial intelligence entrepreneur Demis Hassabis.
Another section saw Met Police Commissioner Cressida Dick interviewed.
Prince Harry chose Abdurahman Sayed, from the Al-Manaar Muslim Cultural Heritage Centre in North Kensington, which has been helping residents following the fire in June at the nearby Grenfell Tower, to speak in the programme’s Thought for the Day spot.
Speaking about his editing role, Prince Harry said: “I haven’t done that many interviews but it was quite fun, especially interviewing President Obama.
“It’s been a big learning curve, but also these are incredibly important topics that I think we all need to think about that need to be discussed and I’m incredibly fortunate to have a platform like this.”
Harry ‘bouncing towards the new year’
By Jonny Dymond, BBC royal correspondent
One claims to speak for the nation and one claims to speak to the nation. On Radio 4’s Today, the Royal Family and the BBC came together in a cosy embrace.
Few of the prince’s causes were unrepresented and he was himself dotted through the programme, encouraging and enthusing about nearly everything.
He is clearly bouncing towards the new year, a time he insisted would be full of “great change – good things are going to happen in 2018”.
There was little in the way of actual hard news – former US President Barack Obama has more time on his hands these days; the Prince of Wales; “Pa” as Harry called him, is concerned about the environment; Harry doesn’t drink coffee, or much of it.
But there were glimpses of the gilded cage. A note of wistfulness in his voice when he asked Mr Obama about “stepping off the treadmill” of constant exposure.
Prince Harry, who was in the Army for 10 years, said he wanted to include an item about the armed forces because “there’s a huge role that they play and we must make sure it’s not sympathy but it’s respect we show”.
During the programme, the Prince of Wales said he had “bored you [the prince] to tears over so many years” with discussions on the environment but the public was “beginning to realise that what I was trying to say may not have been as dotty as they thought”.
Prince Charles added he wanted to “ensure that you and your children, my grandchildren… have a world fit to live in, that provides them with opportunity”.
Mr Obama reflected on his time in office and voiced concerns about the direction the United States is moving in.
He warned that social media was stopping normal conversations and talk about the responsibility of people in positions of leadership.
Mr Obama expressed concern about a future where facts are discarded and people just read and listen to things that reinforce their own views.
In one of his first interviews since leaving office, the former president also reflected on the day he handed over power to Donald Trump.
Despite feeling satisfied, he said it was “mixed with all the work that was still undone.”