Heavy rain didn't deter streams of family, friends and fans from celebrated film critic Roger Ebert's funeral in Chicago Monday morning.

The packed Catholic service began at 11 a.m. local time at Chicago's downtown Holy Name Cathedral. Mourners included Chicago Mayor Rahm Emanuel.

Ebert, the longtime Chicago Sun-Times writer who was the first critic ever honoured with the prestigious Pulitzer Prize, died Thursday at the age of 70 after a long battle with cancer.

His death came just days after he revealed that his cancer had returned. On Saturday, the paper published his final review — a look at Terrence Malick's To The Wonder.

Though he became a household name for his "thumbs up, thumbs down" movie-review TV show with fellow reviewer Gene Siskel in the late 1970s and early '80s, Ebert gained a massive new audience in recent years through blogging and Twitter after multiple cancer surgeries left him unable to speak.

Another public memorial for Ebert is scheduled for Thursday evening at the Chicago Theater and will include music, tributes and excerpts of Ebert's show At the Movies.

Ebert was praised during his memorial Monday as a consummate Chicago newsman, a champion of storytellers and a visionary who understood the power of social media to spread the word about good movies.

"He didn't just dominate his profession, he defined it," said Chicago Mayor Rahm Emanuel, who praised him as a newsman and critic.

Jonathan Jackson, son of civil rights leader Rev. Jesse Jackson, paid tribute on behalf of his father who could not attend the service. He told the crowded church that Ebert had supported black filmmakers decades ago when this was something that just wasn't done.

"He respected what we had to say about ourselves," said Jackson, who pointed to Ebert's glowing review of Spike Lee's Do The Right Thing in the late 1980s. "It was not his story but he understood the value of an important film was authenticity and not the fact that it depicted your interests."

Ebert has been widely praised for his embrace of social media, particularly Twitter, which he used to keep readers up with his thoughts about movies, his wife, Chaz, and anything else that popped into his head after multiple surgeries left him unable to speak.

"He realized that connecting to people was the main reason we're all here and that's what his life was all about," said Sonia Evans, his stepdaughter.

With files from The Associated Press