The Duke of Cambridge attends the London Air Ambulance Charity Gala

The transcript introduces the Duke of Cambridge as a patron of a charity event, welcoming attendees to London's Air Ambulance gathering after a three-year break. The speaker adds humor by offering to share jokes privately and commends themselves for self-control. The evening will focus on celebrating the event's return.

What is the speaker's attitude towards self-control during the event?

What is the main purpose of the event as mentioned in the speech?