Darren Criss is mourning the great loss of his beloved dad.

The Golden Globe winner took to social media on Monday evening to announce the death of his father, Charles William

Darren Criss is mourning the great loss of his beloved dad.

The Golden Globe winner took to social media on Monday evening to announce the death of his father, Charles William Criss, Jr., who passed away just ahead of his 79th birthday in May.

"Bill Criss has left the building. After many years of coping with a rare heart condition—which, true to his form, very few would have even been aware of—he finally checked out peacefully yesterday morning, surrounded by his loved ones," the star shared on Instagram before further reflecting on the special man his father was.

"Dad lived an extraordinary life. Anyone who ever met Bill Criss adored him instantly. He could talk to anyone about anything. Well-read and well-traveled, he made the world a better place wherever he went. He was as deliriously charming as he was relentlessly selfless; always putting other people first, making anybody who ever got into a conversation with him genuinely feel like they were the most incredible person in the room," Darren described. "And although he would have been the first to gracefully protest it, the simple truth is that he was in fact, every inch the exemplary man: a devoted husband, an outstanding father, a loving grandparent. He lived his days the same way he loved his friends and family—with an unwavering sense of composure, compassion, generosity, and humility."