Former RSC artistic director Terry Hands recalls directing her in Tamburlaine The Great in 1993.
"She had a rhythm all her own," he says. "If you let her go free she did extraordinary things."
Since then Okonedo has balanced motherhood with dozens of television, radio, theatre and film roles. She now lives in Muswell Hill with daughter Aoife, seven, by Irish film editor Eoin Martin.
Her Oscar nomination was so unexpected that when the results were announced she was visiting an art gallery with her mother. "At one stage in my career I didn't think I'd ever make a film, so to be nominated for an Oscar is overwhelming," she says. "I've spent 15 years plugging away and the last year has been amazing."