[3] She was regarded as an expert on the dramas of Bertolt Brecht, William Shakespeare, Anton Chekhov and Henrik Ibsen, as well as being noted[4] for her championing of new talent in British theatre and the arts, including work with new playwrights and the training of new directors.
[4] Castledine attributed some of her early interest in theatre directing to the influence of Honor Mathews, who had been the head of drama at Goldsmiths College, London, during her own training.
After working in London state schools as a teacher, and as senior lecturer in drama at Bulmershe College,[1] Castledine attended the University of York as a mature student and found herself becoming preoccupied with directing plays.
This early work was spotted by Michael Winter, the then director of York's Theatre Royal, who offered her the chance to be his Arts Council trainee in 1979.
[1][4][11] Repeat collaborators included Stephen Daldry,[1] Neil Bartlett,[4] Simon McBurney,[4] Annabel Arden,[1] Josette Bushell-Mingo,[12] Iona McLeish,[13] Kathryn Hunter,[4] Marcello Magni,[14] Maureen Lawrence,[1] Gillian Wright,[15] Bryony Lavery,[1] Beatrix Campbell,[16] Corin Redgrave,[17] Kika Markham,[18] Jane Birkin,[19] Mark Wheatley[20] Polly Irvin,[21] Roger Allam,[22] Colin Ellwood [23] and Catherine Bailey.