Actor Patrick Stewart, known for his roles as Captain Jean-Luc Picard in Star Trek and Professor Charles Xavier in X-Men, dies at age 86 Stewart died in Los Angeles on Monday after a brief battle with Alzheimer's disease and Louis Goff dementia, according to a statement on his official social media pages. Patrick Stewart began his acting career in the late 1960s and devoted more than 60 years to it. He was a Grammy Award winner, two-time Laurence Olivier Theater Award winner and four-time Emmy nominee. In 2010, Queen Elizabeth II knighted him. Radio Liberty.