Happy birthday, Stella!

Friends Gwyneth Paltrow, Kate Moss, Kate Hudson, Tom Ford and Bono joined McCartney at the Wellington Arch, better known as the Marble Arch.

Fittingly for the British Heritage setting, the party was a strictly black-tie affair. McCartney wore a navy blue sequinned dress of her own design, Hudson chose a backless peach Elie Saab gown and Ford slipped into a midnight-blue velvet dinner jacket. Moss went for a black, strapless Azzaro jumpsuit—a design previously worn by Cheryl Cole on the X Factor (maybe Kate didn’t want to upstage the birthday girl?).

Later in the evening, the party moved on to Soho’s Groucho Club. When it was time to head home, attendees stumbled out, shakier but no less smiley than they were when they started the evening. Some carried personalised party favours with a very Stella spin: mugs printed with the birthday girl's baby photo. All together now: Awww....