(TMZ)Roger Ebert -- one of the most famous movie critics of all time -- died today after a battle with cancer.

He was 70 years old.

Ebert is a legend in Hollywood who popularized the use of  the "Thumbs Up, Thumbs Down" ratings system Ebert's movie reviews were considered to be the most influential in town.

Aside from writing movie critiques for the Chicago Sun Times for 46 years, he also hosted "At The Movies" from the early 80s until 2006.

Ebert was famously joined on the show by fellow critic Gene Siskel, who passed away in 1999.