Michael Sheen, a global star of screen and stage, is spearheading a new national theatre for Wales, promising to create big, bold plays that bring vital stories about his homeland to life.

Sheen said he was bursting with ideas and promised to appear in the newly forged Welsh National Theatre’s first production, a “foundation” story about Wales staged at the Wales Millennium Centre in Cardiff.

The actor, who has been announced as artistic director of the theatre company, told the Guardian that Wales’s stories were “under-explored in the English language”.

Sheen said: “Could you tell me the name of the great play about Aberfan or the Merthyr Rising or the Rebecca riots? Where is our Welsh canon of great plays? We can’t do Under Milk Wood for the rest of eternity. I’m bursting with ideas people are bursting with work that they want to do with us and that’s what’s really exciting about it.”

Just before Christmas, National Theatre Wales, which was established in 2009, announced it had “ceased to exist” after its Arts Council of Wales funding was cut. It has evolved into Team (theatre, education, arts, music), focusing on grassroots work.

Sheen said his new company did not yet have funding. “But that suits my way of thinking. I like the idea of starting small, simple, lean and building it up, working with what you’ve got. Don’t pay for swanky offices if you don’t need them, build it slowly with care and with passion and with vision and with ambition.

“We aim to represent the Welsh people so I would hope that public bodies would be prepared to work with us. I think probably history tells us that relying too much on any one source of funding makes you a bit vulnerable so I first and foremost would hope that this company can stand on its own two feet but we are open to working with whoever wants to get involved.”

Sheen said he was thinking big.

He said: “My instinct has always been, rightly or wrongly, that when people around you are saying: ‘No, you can’t have that, you can’t do that,’ to go even bigger and bolder and go, no we’re not going to do that, we’re going to do 10 times that.”

Sheen said he was not in a position to reveal details of performances but said the plan was to do one production a year. “The plan to begin with is do big plays really well for big audiences. I’m starting to commission writers.”

Sheen said he was also speaking with organisations such as Welsh National Opera and the Welsh language company Theatr Cymru about working together.

He said: “I’m talking about big bold ambitious world stage productions of plays about who we are, where we’ve come from, how we got to where we are and where are we going.

“The first production will be on the Millennium Centre stage. It will be a new Welsh play, it will star Welsh actors including myself, and it will be one of the foundation stories of who we are as a nation.” Sheen said the first production should be staged next year.

He was working on Nye, the hugely successful play on the life of the Welsh politician and NHS architect Aneurin Bevan, at the National Theatre in London last year when it became clear that National Theatre Wales was in deep trouble.

The company was close to Sheen’s heart as he starred in and co-directed its most celebrated work, The Passion, a modern re-telling of the crucifixion featuring hundreds of local people. “That was a life-changing experience for me,” he said.

Sheen spoke to fellow Welsh actors about what should come next. “I realised I was probably the leading candidate for what could happen now. My feeling was very strongly that it should be a completely new company. It should be a fresh start, a new charity, a new board of governors. I didn’t want to take something over I wanted to start afresh.”

When Nye transferred to the Wales Millennium Centre in Cardiff, the experience reinforced Sheen’s determination to launch a new national theatre for Wales.

Sheen said: “You know that phrase: ‘Build it and they will come.’ It was rammed every performance – they were bringing chairs from the bar to get more people in. The appetite for it was extraordinary and it was hugely moving to perform that to a Welsh audience. People were seeing a play about them and their lives and their history and their story. That was revelatory to me.”