Sir Patrick Stewart, the British actor who became a global television and film icon through his portrayal of Captain Jean-Luc Picard in Star Trek and Professor Charles Xavier in X-Men, has died at 86 after battling Alzheimer’s disease and Lewy body dementia.

His death was announced on Thursday in a statement shared through his official social media accounts, which said he died at his home in Los Angeles on Wednesday, surrounded by family and friends and in the care of his wife, Sunny.

The statement described his final moments as peaceful, saying he was surrounded by music, prayers, tears and laughter.

Stewart’s death brings to a close an acting career spanning more than six decades, during which he moved from classical theatre to some of the most successful science-fiction and superhero productions in film and television.

Before becoming internationally famous as Captain Picard, Stewart built his reputation as a Shakespearean actor and spent years performing with the Royal Shakespeare Company, which he joined in 1966.

He made his Broadway debut in 1971 in A Midsummer Night’s Dream before going on to establish himself as one of Britain’s respected stage performers.

His international breakthrough came in 1987 when he took the role of Captain Jean-Luc Picard in Star Trek: The Next Generation, a character he played for seven television seasons and several films.

He later gained another generation of admirers as Professor Charles Xavier, the leader of the X-Men, appearing in several instalments of the popular superhero franchise.

Stewart was knighted in 2010 for his services to drama and remained active in film, television and theatre across his career.

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

His death has drawn tributes from colleagues and fellow actors, who have remembered his contribution to theatre, television and cinema.