The late Muhammad Ali is getting the Ken Burns treatment. The PBS documentarian announced Tuesday that he and two partners will make a two-part, four-hour film about the former heavyweight champ, who died last June. Burns, his daughter Sarah and David McMahon collaborated for a PBS documentary on Jackie Robinson that debuted last year.

The tentative plan is to air the Ali film in 2021.

Sarah Burns said the outpouring of good will at Ali’s death made it easy to forget how divisive it was when the former Cassius Clay took the Ali name when he converted to Islam and refused to join the Army during the Vietnam War. She said filmmakers want to examine what influenced Ali’s choices and how he stuck with them despite public condemnation.