The Crown: Queen Elizabeth's sister puts monarchy at risk

After giving her consent to Princess Margaret's marriage to  Peter Townsend, Queen Elizabeth is informed that the wedding would put the monarchy at risk.

In "The Crown" episode "Gelignite" the young Queen is warned about the news story that's about to break in the British press about her sister's love affair with their father's loyal man.

The Queen is advised to send the pair away in order to divert media's attention.

The Group Captain Peter Townsend, a divorced commoner, is forced to leave the UK for Brussels where he is assigned a diplomatic role.