Vanessa Kirby looks sensational in a backless gown with a leg slit as she joins elegant Rooney Mara at Napoleon world premiere in Paris

Vanessa Kirby looked sensational as she joined Rooney Mara at the Napoleon world premiere in Paris on Wednesday.

Walking the red carpet at Salle Pleyel, the actress, 35, who plays Napoleon Bonaparte’s wife Empress Joséphine in the film, wore a black backless gown.

She made sure to turn heads in the dramatic number that featured a thigh-high leg slit and a small train with metallic gold embellishment.

Joining her at the event Rooney, 38, opted for an elegant off-the-shoulder crop top with a semi-sheer chiffon skirt.

She elevated her height with a pair of black stiletto heels and pulled her hair back into a sleek bun.

Glamorous: Vanessa Kirby (L), 35, looked sensational as she joined Rooney Mara (R), 38, at the Napoleon world premiere in Paris on Wednesday

Stunning: Walking the red carpet at Salle Pleyel, the actress wore a black backless gown

Rooney stepped out to support her fiancé Joaquin Phoenix, who stars as the eponymous leading role in Sir Ridley Scott’s upcoming epic, which is set for release on November 22.

Joaquin, 49, joined his co-star Vanessa for a photo, putting on a smart display in a black suit and tie.

The premiere comes as Ridley Scott has slammed TV historian Dan Snow for criticising his upcoming historical epic Napoleon.

Snow, 44, picked out historical inaccuracies in the $200million film which stars Joaquin Phoenix as the French military commander.

The historian pointed out that Napoleon did not fight at the pyramids nor did he ever witness Marie Antoinette’s execution.

Snow also took issue with the film’s tagline, ‘He came from nothing, he conquered everything,’ because Napoleon never conquered Britain.

‘I love historical epics. I love Ridley Scott. But if you’re watching this movie, it ain’t a documentary,’ Snow said.

Ridley did not have much time for Snow’s criticisms however, as he told him to ‘get a life’ in an interview with The New Yorker.

Incredible: She made sure to turn heads in the dramatic number that featured a thigh-high leg slit and a small train with metallic gold embellishment

Sophisticated: Vanessa, who plays Napoleon Bonaparte’s wife Empress Joséphine in the film, carried a matching clutch bag

Pretty: Joining her at the event Rooney opted for an elegant off-the-shoulder crop top with a semi-sheer chiffon skirt

Radiant: She elevated her height with a pair of black stiletto heels and pulled her hair back into a sleek bun

VIPs: Rooney stepped out to support her fiancé Joaquin Phoenix, who stars as the eponymous leading role in Sir Ridley Scott’s upcoming epic (Joaquin pictured with Vanessa)

Star: Joaquin, 49, joined his co-star Vanessa for a photo, putting on a smart display in a black suit and tie

While Snow may not have been impressed, Ridley’s military adviser on the film, former paratrooper Paul Biddiss insisted the director put much care into the project.

‘Uniformity is very important with Ridley — right down to the guys, making sure their hats are straight,’ he said.

Napoleon Bonaparte, later known by his regnal name Napoleon I, was a Corsican-born French military commander and political leader.

He gained fame during the French Revolution and led successful campaigns during the Revolutionary Wars.

The film explores Napoleon’s climb to power through his relationship with his wife Josephine.

It will see Phoenix star opposite Vanessa Kirby, who played Princess Margaret in The Crown, after Killing Eve star Jodie Comer was forced to pull out.

It is also the first time Phoenix has been reunited with director Sir Ridley Scott since starring in Gladiator in 2000.

The film was previously titled Kitbag which referred to the saying: ‘There is a general’s staff hidden in every soldier’s kitbag.’

The expression means it is possible for any soldier to become a general.

Pose: Director Ridley Scott was joined by his wife, producer Giannina Facio, and Vanessa on the red carpet

Drama: The premiere comes as Ridley Scott has slammed TV historian Dan Snow for criticising his upcoming historical epic Napoleon

Blockbuster: Snow, 44, picked out historical inaccuracies in the $200million film which stars Joaquin Phoenix as the French military commander

Speaking about the film, Sir Ridley said: ‘Napoleon is a man I’ve always been fascinated by.

‘He came out of nowhere to rule everything –but all the while he was waging a romantic war with his adulterous wife Josephine.

‘He conquered the world to try to win her love, and when he couldn’t, he conquered it to destroy her.

‘No actor could ever embody Napoleon like Joaquin.’

Napoleon opens in theatres on Wednesday November 22.