Patrick Stewart, the classically trained actor who added Shakespearean gravitas to the “Star Trek” and “X-Men” franchises, has died. He was 86.

Stewart died Wednesday in Los Angeles, following “a brief and poignant journey” with Alzheimer’s disease and Lewy Body Dementia, spokesperson Kelly Bush Novak said. Stewart’s diagnoses had not been previously disclosed.

“We lost one of the greats of stage and screen today,” Hugh Jackman, a frequent Stewart co-star in the “X-Men” universe, said on social media. “And, in my book, a tremendous friend and man. I learned so much from him.…