Mark Ruffalo to Star in HBO Limited Drama Series 'I Know This Much Is True'

HBO Eight-Episode Limited Drama Series

In Development


I KNOW THIS MUCH IS TRUE is an epic family saga that explores the American identity following the parallel lives of twin brothers Dominick and Thomas Birdsey throughout the latter half of the 20th century.

BR 001239_b4e8f4dc89104ca87957a8fadebfcf42.jpg


Writer/Director/Executive Producer: Derek Cianfrance
Executive Producer: Mark Ruffalo
Executive Producer: Wally Lamb 

Executive Producers: Ben Browning & Glen Basner for FilmNation Entertainment

Based on Wally Lamb’s award-winning book I KNOW THIS MUCH IS TRUE.


Mark Ruffalo set to star as twin brothers Dominick and Thomas Birdsey

Biography Information

Mark Ruffalo is a three-time Oscar-nominee,Tony award nominee and Emmy award winner. His film credits include “You Can Count on Me,” “Eternal Sunshine of the Spotless Mind,” “Collateral,” "Spotlight,” “The Kids Are All Right,” Infinitely Polar Bear,” “Now You See Me,” and “Foxcatcher.” His television credits include HBO’s “The Normal Heart” for which he won the Screen Actors Guild Award. Theatre credits include “This is our Youth,” “Awake and Sing” and Arthur Miller’s “The Price.” Ruffalo executive produced “The Normal Heart,” which won the Emmy for “Outstanding Television Movie" as well as the documentary “Dear President Obama,” and the feature “Sympathy for Delicious," which he also directed. He will next be seen in “Thor Ragnarok” the most recent film in Marvel’s global “Avengers” franchise in which he stars as 'Bruce Banner/The Hulk.’

Derek Cianfrance’s previous work includes THE PLACE BEYOND THE PINES starring Ryan Gosling, Bradley Cooper and Eva Mendes and BLUE VALENTINE starring Ryan Gosling and Michelle Williams. 

Wally Lamb is the author of six New York Times best-selling novels: I’ll Take You ThereWe Are WaterWishin’ and Hopin’, The Hour I First BelievedI Know This Much is True, and She’s Come Undone and was twice selected for Oprah’s Book Club. Lamb also edited Couldn’t Keep It to Myself and I’ll Fly Away, two volumes of essays from students in his writing workshop at York Correctional Institution, a women’s prison in Connecticut, where he has been a volunteer facilitator for the past 18 years.  

FilmNation Entertainment is the independent film company behind Academy Award winning ARRIVAL and breakout box office hit THE BIG SICK.