Sir Ian McKellen leads tributes to 'beloved actor' Sir Patrick Stewart after his death at 86

Sir Ian recalled first meeting Sir Patrick as young actors in the Royal Shakespeare Company (RSC) and how he had expressed caution over him taking on the Star Trek role.

"He took the risk and thank goodness for us all that he did," said Sir Ian, who appeared with Sir Patrick in a 2009 theatre production of Waiting for Godot.

He added that while the US had become Sir Patrick's "adopted home", he "never forsook his origins" growing up in Yorkshire, and said "the proudest achievement of the most respected and beloved actor of his generation on either side of the Atlantic, was his appointment as chancellor of Huddersfield University".

Sir Ian noted that Sir Patrick's final film appearance will be as Professor X in the upcoming Avengers: Doomsday film. Marvel Studios described him as "a singular talent, a generous collaborator and a true gentleman".

The Academy dubbed his voice "unmistakable", adding: "Whether commanding the bridge of the Enterprise or guiding a generation of young mutants, Sir Patrick Stewart brought a tenderness to his characters that made us feel we knew them."

Sir Patrick died on Wednesday "in the loving care of his wife", a statement from his family said. "We will forever cherish the peaceful ease and reflection on his face, an enduring reminder of his invincible grace," it added.

The veteran actor is survived by his wife, Sunny Ozell, as well as by his two adult children from his first marriage, Daniel and Sophie Stewart.

Dame Harriet Walter, who first met Sir Patrick in his theatre days more than 40 years ago, said his passing was like a "huge giant tree has fallen in the forest".

"He had fire in his eyes and you were absolutely in the room with him," the Succession actress told BBC Newsnight. "I've never heard a bad word against him. And I think the world's going to be very poor without him."

Hannah Essex, co-chief of the Society of London Theatre and UK Theatre, called him "one of the greatest stage actors this country has ever seen".

As well as having roles in films such as Safe House, Robin Hood: Men in Tights and the original Dune, Sir Patrick continued to appear on TV throughout his career, making guest appearances on Frasier, Futurama and the Simpsons.

US actor and animator Seth MacFarlane, who grew up as a fan of Sir Patrick, said he was "gifted the privilege of becoming a colleague and friend" as they worked together on Family Guy, American Dad! and Ted.

MacFarlane described him as a "rare actor who could take any bit of dialogue and elevate it, making a good writer sound great and a great writer sound masterful".

Sharing a video of the pair giggling in a set of bloopers for the series, Gervais said: "I still can't believe he agreed to do this scene. And he didn't even mind when I ruined every take."

"Fiercely proud of his Yorkshire roots, Sir Patrick was a Terrier in every sense, and we're proud to have counted him as one of our own," the club added.

Alzheimer's is the most common type of dementia, while Lewy Body Dementia is another common form caused by abnormal protein deposits, which cause a loss of cognitive function.

The Alzheimer's Society CEO Michelle Dyson said Sir Patrick was an "extraordinarily talented and much-loved actor, admired by millions around the world", adding: "His death is a heartbreaking reminder of the devastating impact dementia has on people and families across the globe."

The actor became a campaigner on domestic violence in later life, including becoming an ambassador for domestic abuse charity Refuge in 2007, after witnessing his mother suffer violence at the hands of his father.

Hetti Barkworth-Nanton, Refuge's board chair, said it had been a privilege to "watch his endless devotion" to the cause, adding that he "broke down barriers and taboos on the subject".

"He brought joy to millions," the prime minister's spokesman said on his behalf. "He always stood up for what he believed in, including through his campaigning to help those affected by domestic violence.