FHM magazine model Bonang Matheba hosted the evening and joked she wanted to get the prince dancing.
The famous South African presenter wore a skin-tight white dress and said: "I told him he should loosen up and have some fun - I will show him some South African dances."
More top news
The prince laid a floral wreath at one of a group of metal crosses near Wellington Arch in central London.
The group, which also owns Premier Inn, said on Wednesday that it will pursue a ‘demerger of Costa’.
The showers will become more frequent as the day goes on, giving some heavy downpours in places during the afternoon.