If you’re off to Ascot in the next few days, entry is virtually forbidden without a fascinator, and you’ll be wanting something stylish and genteel to wear under your arm, too. Think of it as a wedding where you’re actually encouraged to upstage the bride.

Steve Buscemi and Sienna Miller, at the Cinema Society and ,Dior Beauty screening of Interview at the Tribeca Grand.

Sienna Miller and Mario Testino.

Sienna Miller, in Burberry, with the designer, Christopher Bailey.

Mena Suvari, in Calvin Klein Collection, with Sienna Miller, in vintage Calvin Klein, at a party for the house’s two new fragrances, ckIN2U.

Sienna Miller, in Thomas Wylde.

Sienna Miller, in a dress specifically created for Moët & Chandon by Matthew Williamson.

Sienna Miller – Vogue London Fashion Week Cocktail

Sienna Miller – BAFTA Awards

Sienna Miller, in Dior.