Hugh Bonneville says "goodbye" to Downton Abbey and "hello" to Viceroy's House

"Saying goodbye has been a bittersweet thing," the British actor said, adding that filming the series for six months of a year had become his norm, and the Downton Abbey cast and crew "have become very much a second family to me.

"It's lovely to be associated with a show that's become so popular around the world; but I'm a realist and the show will fade in time, and I'll go back to being known as 'Hugh Bonneville, the actor'" - which is not what he had planned as a teenager.

His interest in the history of the Bible and of Rome led him to study theology at the University of Cambridge. He thought he'd study law after that.

His life took a dramatic (pun intended) turn during his time at Cambridge as he realised he'd like to try acting. He gave himself three years to try it out. All these years later, he says, "I'm still giving it a go."

Looking back, his career choice perhaps shouldn't have come as a surprise. As a kid, he'd drag his siblings to watch his plays - which he wrote, dressed up for, and even made tickets for. He asked his friends, who'd rather play football, to be in the performances in which he was, of course, the star.

However, making a living through acting is not easy. Bonneville's number one piece of advice for anyone who's thinking of entering the industry is this: "If you draw up a shortlist of three jobs you like to do, one of which is acting, then you shouldn't be an actor.

"It has to be the only thing you believe you can do. It has to be a passion, because there's an enormous amount of rejections along the way. You have to have both a thick skin to take the rejection, and a thin skin to allow you to be in touch with your emotions, expressions, confidence and vulnerability."

Bonneville was in Hong Kong as part of the Bafta initiative, which encourages creative collaborations between the British and Hong Kong film, TV and games industries. During his 24 hours here, he hosted a fundraising dinner, visited two local schools, and hosted a public masterclass. "Hugh has got an incredible body of work which is both fascinating and inspiring … He wants to share his experiences and to give something back," says Bafta chief executive, Amanda Berry.

At Cotton Spinner Association Secondary School in Kwai Chung, Bonneville, a life-long Shakespeare fan, used his skills to help students with a scene from Macbeth.

Given that love of The Bard, it was natural that Bonneville began his professional acting career on the stage. But he says that experience is very different from the medium for which he's become famous.

"On stage you reach out, on screen you let the camera in."

The other difference, he added, is that "on stage the actor is the most important cog in the machine … on the film set, you're the least important person", because the crew is really what keeps the projects going.

With his warm and friendly face, Bonneville doesn't get the heartthrob roles, but he also doesn't get the pressure to keep fit. "I was told I was too fat to play Hamlet once; disappointing, but that was about it," he says.

But when he auditioned for the part of Bernie the dim stockbroker in Notting Hill, he had just lost 9kg. The director phoned him after the audition saying, "We need to have a conversation about your weight."

"No, I'm trying, I'm really, really trying."

"You're too thin; Bernie is meant to be fat."

Bonneville's response was: "I'm sorry, but I'm not going back." Luckily, he kept the role, but the writers had to rewrite a few lines referencing Bernie's chubby cheeks.

Although Bonneville's saying goodbye to Lord Grantham, he's clearly not ready to leave behind the aristocratic lifestyle just yet - he'll return next year as Lord Louis Mountbatten in Viceroy's House, and this time, with 500 servants downstairs.

In the British-Indian historical drama, Bonneville plays the last Viceroy of India in 1947. "The difference between him and Lord Grantham is that he was real. So it was really interesting to learn more about him and this incredibly delicate task he had of withdrawing British power from India and handing over as safely as possible."

If his turn as the Earl of Grantham is anything to go by, we have no doubt he'll portray this aristocrat with impeccable style.