Henry V (1989)
Kenneth Branagh's 1989 directorial debut. Mud and blood Agincourt instead of Olivier's pageantry.
Derek Jacobi had a pronounced stammer as a child and found that it disappeared when performing, which is a common enough story and rarely leads to this.
I, Claudius on television is the defining work, playing an emperor who survives by pretending to be a fool, across thirteen episodes and fifty years of narrative.
Gladiator, Henry V and Dead Again fill out the film career, and he has played Hamlet, Richard II and Lear on stage. He was knighted and holds two of the rare Shakespearean distinctions.