Actor Ian McKellen has shared a heartfelt social media tribute to his longtime friend and collaborator Patrick Stewart, who passed away on Thursday at the age of 86 following battles with Alzheimer’s disease and Lewy Body Dementia.

Writing on Instagram, McKellen reflected on Stewart's Yorkshire roots, describing him as a man of stern honesty who wore his heart on his sleeve. The two initially crossed paths half a century ago as ambitious young actors with the Royal Shakespeare Company before cementing a legendary bond decades later when they starred as Professor X and Magneto in 2000's X-Men.

Beyond their shared cinematic universe, which included multiple X-Men sequels and the upcoming December release Avengers: Doomsday, the pair shared a rich history on stage, performing together on Broadway and in London's West End. McKellen also notably officiated Stewart’s 2013 wedding to Sunny Ozell.

McKellen concluded his tribute by noting Stewart's enduring connection to his origins and highlighting his final screen appearance in the upcoming Avengers: Doomsday.