Robin Williams' children pay heartfelt tribute on his 72nd birthday

Robin Williams died in 2014 at the age of 63; his children recently paid tribute to their father and remembered the legacy of their late father.

Taking to social media, the late actor's daughter, Zelda Williams and son, Zak Williams, paid tribute to their father and celebrated what would have been his 72nd birthday.

According to People magazine, Zak shared a throwback photo of his father on his Instagram page. The picture saw his father wearing headphones and smiling while looking into the camera.

He captioned the post, "Happy 72nd Dad! Was remembering how much I used to love that look you'd give. That look with a mischievous, loving grin that your friends and loved ones knew so well. Joyous and curious and wondrous. Miss you and love you forever!"

His daughter took to Twitter to pay tribute to her father. 

She shared a photo of her late father joining the New York picket line in the 2007 strike. The photo saw Robin standing with fellow protestors holding a sign that said, "SAG WGA ON STRIKE."

She wrote, "Happy birthday to Poppo, who definitely would've been out there fighting the good fight for art and artists today and always."

Robin starred in Jumanji ,and was outspoken in advocating the rights of artists.