Patrick Stewart was an actor.

He was classically trained.

He brought Shakespearean weight to “Star Trek” and “X-Men.”

He died at 86.

A spokesperson, Kelly Bush Novak, said he died Wednesday in Los Angeles.

The cause was Alzheimer’s disease and Lewy Body Dementia.

This was not known before.

Hugh Jackman often acted with him in “X-Men.”

He called him one of the greats of stage and screen.

He also called him a tremendous friend.

Stewart was best known as Captain Jean-Luc Picard.

He was also known as Professor Charles Xavier.

But he spent more of his career onstage than on screen.

He played roles from Claudius to Macbeth.

He often performed a one-man “A Christmas Carol.”

He appeared on the West End and Broadway.

He acted in plays by Harold Pinter and Samuel Beckett.

He acted alongside his friend Ian McKellen.

His 2007 Macbeth was directed by Rupert Goold.

It earned him his only Tony nomination.

It also earned strong reviews.

Stewart grew up in a working-class family in Mirfield, Yorkshire.

His house had no bathroom.

He joined an amateur drama group at 12.

He won a scholarship to the Bristol Old Vic Theatre School.

He was bald from age 19.

Alopecia runs in his family.

In his memoir, he wrote about his father’s violence against his mother.

He later became a patron for Refuge.

Refuge shelters domestic abuse victims.

Stewart spent 14 years with the Royal Shakespeare Company.

Then he left for more varied work.

In 1987 he took a role in a syndicated science fiction series.

He was told it would fail.

“Star Trek: The Next Generation” instead ran seven years and 178 episodes.

It led to four films.

He was knighted in 2010.

He is survived by his wife, Sunny Ozell, and two children.