20 years ago, Alan Bennett’s ‘The History Boys’ opened at the National Theatre, and a classic was born. The show become a launch pad to stardom for many of its original cast members including Dominic Cooper, James Cordon, Sacha Dharwan, Russell Tovey, Jamie Parker, Andrew Knott and Samuel Barnett, whilst, in its own right, became famous for being a stark look at the education system through the positives and negatives of examinations and knowledge for knowledge’s sake.   20 y