LOS ANGELES — Legendary English actor Patrick Stewart, widely celebrated for defining generations of science fiction and classical theater through iconic roles like Captain Jean-Luc Picard and Professor Charles Xavier, has died. He was 86.

According to a statement shared via his Instagram account, Stewart passed away Wednesday at his home in Los Angeles following a brief battle with Alzheimer's disease and Lewy Body Dementia.

Over a career spanning decades, Stewart established himself as a towering talent across stage and screen. Before achieving international superstardom in 1987 as the moral center of the Starship Enterprise in Star Trek: The Next Generation, he spent two decades as a principal mainstay of the Royal Shakespeare Company. His extensive stage credits included acclaimed performances in Macbeth, The Tempest, and Hamlet, for which he earned an Olivier Award.

Stewart is survived by his third wife, Sunny Ozell, and his two children, Sophie and Daniel Stewart, from his first marriage.