'70s icon Bianca Jagger, 81, makes rare appearance in London for George Cloooney

For the gala, Bianca wore a chic black satin skirt that hit above the ankles with a matching black single-breasted blazer.

She added a crisp white shirt with the sleeves purposefully extending past the blazer and the collar popped upwards.

The style icon added black leather gloves, tights and a chunky black platform sandals to her look, but it was what appeared to be a Gucci cane that was the star of the show.

Bianca finished her look with a bold red lipstick and oversized mixed-material earrings.

It's a look that has in some ways become a signature of Bianca's over the years. In March she wore something very similar during Paris Fashion Week, pairing a white shirt with a black lace top and sleek black leather coat, as well as her gloves. 

A month earlier, she wore black pants with a blazer – and her gloves – at the Ballet Icons Gala 20th Anniversary gala.

Bianca is perhaps best known for rising to international prominence in the 1970s as the first wife of Rolling Stones frontman Mick Jagger, but she is also a model and activist; she was inducted into the International Best Dressed Hall of Fame in 1976.

She was born in Nicaragua, on 2 May 1945 and moved to France at the age of 18 to study political science during which time she was heavily influenced by Gandhi's non-violent success and Eastern philosophy at large.

By the mid 1960s she had met Michael Caine in Paris and she moved to England with him where she met Mick in September 1970. Bianca fell pregnant in early 1971 and they wed in May of that year; they welcomed daughter Jade in October.

Bianca filed for divorce in May 1978 on the grounds of his adultery.

"I played the wife. I was docile and subservient … but groupies weren't an easy thing to get used to. Mick is in some ways misogynist, because there are too many women available to him," Bianca once said.

Throughout the 1970s Bianca became a muse of Andy Warhol's and was closely associated with the iconic NYC nightclub Studio 54; she entered the club on a white horse for her 32nd birthday.

"Bianca Jagger is one of the most Socially Diseased people I know. She's almost as bad as me—and I'm terminal," Andy once said of her. 

"She loves to go out every night to the hottest spot in town and make a big dramatic entrance in a big dramatic dress."

However 1981 was a "turning point" for Bianca as she joined a US congressional delegation inside a refugee camp in Honduras. 

She founded the Bianca Jagger Human Rights Foundation, which she continues to chair, focusing on issues of justice and human rights, and in particular the challenge of ending violence against women and girls across the globe.