Conversation so far:
How did Irvings career begin?
On 29 September 1856 he made his first appearance at Sunderland as Gaston, Duke of Orleans, in Bulwer Lytton's play, Richelieu, billed as Henry Irving.
Was he successful?
the inexperienced Irving got stage fright and was hissed off the stage.
What did he do after this?
For 10 years, he went through an arduous training in various stock companies in Scotland and the north of England, taking more than 500 parts.

Question: What was the result of this?
Self-contained rewrite: What was the result of Henry Irving's arduous training in Scotland and England?