When actress Diane Keaton died early this week, much of the outpouring of public grief for her, and the media adulation of her, focused on her fashion sense.

That’s not because she was a mere clothes horse, or a vacuous “style icon” with nothing else to offer.

Diane Keaton in her signature look – a bowler hat and full skirt with a wide belt. Here she is receiving an award from Woody Allen in 2017.Credit: Chris Pizzello/Invision/AP

Keaton was a notable actress who starred in some of the most important movies in cinematic history – Annie Hall and Godfather movies to name a few.

She won an Oscar, a BAFTA and two Golden Globes.

Rather, it was because Keaton was completely sui generis in a way that no longer exists.

Her clothes were her armour, Keaton freely admitted, particularly her signature bowler hats, which she rarely left the house without. They were a by-product of one of her many insecurities – she hated her hair.

But Keaton’s sartorial armour was an expression of herself, while also being a carapace.

Her style was loose, mannish, comfortable, quirky and completely undone, in a way that is incomprehensible to the current generation of celebrities and movie stars.

She didn’t need to pay someone to tell her how to dress.

She dressed as she liked.

And what she liked to wear was tailored men’s suiting, but always with an informal, girlish flourish.

She would add a pussy bow or a silk scarf, or perhaps a corsage on the lapel of her broad-shouldered blazer.

The most famous image of Keaton’s style is her playing Annie Hall, in Woody Allen’s 1977 film of the same name.

In the most famous scene – a two-hander with Allen on a balcony – she is wearing oatmeal brown, high-waisted Katherine Hepburn-esque trousers, a collared white men’s shirt under a black waistcoat, and a tie.

Diane Keaton wearing seersucker linen at Paris Fashion Week in 2023.Credit:........

© The Sydney Morning Herald