British stage and screen actor Patrick Stewart died at his Los Angeles home on October 28, according to a statement posted on his Instagram account. The statement said he had faced a brief battle with Alzheimer’s disease and dementia.

Radio Svoboda reported the announcement on Thursday, October 29. Stewart’s career stretched from the Royal Shakespeare Company to Broadway, television and major film productions.

He was best known to international audiences as Captain Jean-Luc Picard in Star Trek and Professor X in the X-Men franchise. The latter became one of his most recognizable cinema roles.

Queen Elizabeth II knighted Stewart in 2010 for his services to drama.