Possible Clues:

• Open the drinks party for most of them mentioned in Dispatches
• Open a bottle at party for the Nobel prizes
• Forced Horse and Hound to act as host
• Perform a social duty for guests
• Serve as host at a royal investiture, perhaps?
• Play host
• Host party attended by kings and queens, etc
• Perform a social duty for others
• Preside at award-giving ceremony and offer hospitality
• Act as host or hostess