Conversation so far:
Who founded the Royal Philharmonic?
The conductor Sir Thomas Beecham founded the London Philharmonic Orchestra.
When was the Royal Philharmonic Orchestra founded?
In 1932 the conductor Sir Thomas Beecham had founded the London Philharmonic Orchestra.
What is interesting about the first years of the Orchestra?
In its early days, the orchestra secured profitable recording contracts and important engagements including the Glyndebourne Festival Opera and the concerts of the Royal Philharmonic Society.

Question: Why did he leave?
Self-contained rewrite: Why did Thomas Beecham leave the Royal Philharmonic Orchestra?