Harry Potter's Great British Thespians

Fiona Shaw as Petunia Dursley, 1-3, 5, 7
Petunia, sister of Harry's mother Lily, and her husband Vernon grudgingly assumed the task of raising the boy after his parents' death. Not raising, exactly: more treating him like an unsettled dog and making him sleep in a cupboard under the stairs. Petunia gets a reading both sullen and fluttery from Shaw, 52, the piercingly eccentric Irish actress who has dabbled in film (My Left Foot, Persuasion, The Black Dahlia) but is most revered for playing the title roles — Medea, Electra, Hedda Gabler and a potent, plausible Richard II — in revivals directed by Deborah Warner. She immerses herself so deeply in these parts that she comes out drenched.

• Growing Up with Harry Potter