The star of The Americans, which recently won the Golden Globe Award for Best Television Series - Drama for its final season, will play Perry Mason in a series which reboots the character, taking viewers back to his time as a small-time private eye.
Rhys is replacing Robert Downey Jr, who has long been attached to the project. Instead, the Iron Man star will stay on as executive producer.
HBO gives the following description of the new Perry Mason: "1932, Los Angeles. While the rest of the country recovers from the Great Depression, this city is booming! Oil! Olympic Games! Talking Pictures! Evangelical Fervor! And a child kidnapping gone very, very wrong! Based on characters created by Erle Stanley Gardner, this limited series follows the origins of American Fiction’s most legendary criminal defense lawyer, Perry Mason. When the case of the decade breaks down his door, Mason’s relentless pursuit of the truth reveals a fractured city and just maybe, a pathway to redemption for himself."