[1] He appeared in a Marlowe Society production of Romeo and Juliet at the Phoenix Theatre in London, in 1952, and with the Elizabethan Players in a Richard II in Kidderminster in 1954.
The following year he made his professional London debut in Eugene O'Neill's The Iceman Cometh, directed by Peter Wood, at the Arts theatre.
When in 1964 the company found a permanent base at the Arts Theatre, Cambridge, Robertson became its artistic director, and annually staged three to four classical plays.
[6] Other actors whose careers were effectively launched or enhanced by Prospect included Prunella Scales, Dorothy Tutin and Timothy West, and the company mounted critically acclaimed productions of plays by Shakespeare, Chekhov, Dryden, Gogol and John Vanbrugh, as well as Cottrell's adaptation of E.M. Forster's A Room with a View.
[1] Matters of repertoire also became controversial, when a proposed season for late 1979 - which included the double bill of The Padlock and Miss in Her Teens, to mark the bicentenary of David Garrick's death, and a revival of What the Butler Saw - were vetoed by the Arts Council as unsuitable for touring repertory.