According to The Hollywood Reporter, Ioan Gruffudd has signed on to topline Walden Media's Amazing Grace for director Michael Apted. Albert Finney also has joined the cast.

Based on the life of British anti-slavery pioneer William Wilberforce (Gruffudd), Amazing Grace follows his 18th century political career, which placed him at odds with some of the most powerful men of the time, including the king.

Finney will play John Newton, a Wilberforce confidant. Steven Knight (Dirty Pretty Things) penned the screenplay.