While he's secured his place in history as one of Britain's most prolific rock stars, he's also been known to be quite the devoted family man.

And Sir Paul McCartney stayed true to form on Wednesday night, when he stepped out with his daughter Mary McCartney, 48, and his 18-year-old lookalike grandson Arthur, 18, as he attended a screening of the new film My Generation in London.

Photographer Mary was flanked by her handsome son and father as they posed on the red carpet outside the English capital's BFI Southbank ahead of viewing the Michael Caine-narrated documentary about London in the 1960s.

The Fab Three! Sir Paul McCartney was joined by his daughter Mary McCartney and grandson Arthur as he attended a screening of the new film My Generation in London on Wednesday

For their family night out on the town, former Beatles star Sir Paul looked typically cool in dark rinse jeans and a light blue button-down shirt, over which he wore a black blazer.

The legendary musician linked arms with his daughter, who stepped out in a black top, which she teamed with patterned trousers, while her student son opted for a black ensemble, which included a blazer, polo top and jeans.

Sir Paul was no doubt looking forward to reminiscing about the Swinging Sixties, which is covered in the film, featuring interviews with a number of the stars, including Sir Paul, Marianne Faithfull, Twiggy, Mary Quant and Roger Daltrey.

Linked: The former Beatles star and his eldest biological offspring linked arms as they arrived

Striking a pose: The rocker appeared to be in good spirits as they posed outside BFI Southbank

My generations: Arthur, 18, is Mary's eldest son and also musician Sir Paul's first grandson

Let it be! Macca ditches hair dye No matter how famous he became, Sir Paul McCartney has always stayed in touch with his roots. Now the Beatles star has applied this rule to his hair after dyeing it for years. He was said to even colour it himself after allegedly falling out with a stylist. Sir Paul, 75, finally seemed to be losing his grip on the dye yesterday as he appeared with his grandson Arthur Alistair Donald and eldest daughter Mary McCartney at a film screening. A number of grey roots could be seen, suggesting he hadn’t reached for the bleach in a while. The Liverpudlian was in London to watch My Generation, a documentary about the Swinging Sixties, in which he stars. It was produced by Sir Michael Caine. New York stylist Guy Thomas has previously said he dyed Sir Paul’s hair, claiming they parted in 2012 because the star complained about the bill. Advertisement

The film has also inspired a related exhibition of the same name on London's Carnaby Street, running until March 21st.

Sadly, Sir Michael - who celebrated his 85th birthday on Wednesday - was unable to attend the big showing of his film has he slipped last week and broke his ankle.

'He's on strict doctor's orders to stay at home and rest until he's fully recuperated,' a source told MailOnline of his absence from the event.

Ahead of our opening event unfortunately Michael cannot be with us in person owing to slipping at the weekend and breaking an ankle which he has been ordered to rest.

Arthur, who is Sir Paul's first grandson, was born to Mary and her then-husband Alistair Donald in May 1999. They went on to have a second second, Elliot, now 15. Mary also has two sons with Simon Aboud, her director husband of almost eight years.

In August, Arthur enrolled at America's prestigious Yale University, after leaving £19,545-a-year University College School in Hampstead, north London.

The highly revered Ivy League Institution is the alma mater of five US presidents, including George W Bush and his father, George HW Bush, and sets students back around £54,500 per year for academic fees, board, books and personal expenses.

Resemblance: Arthur bore a striking resemblance to his famous grandfather as he hit the event

Good looks run in the family: The teen sports the same good looks that earned his grandfather legions of fans when he was an 18-year-old budding rock star back in 1960, left

Stepping out in typcially cool style: Sir Paul looked typically cool in dark rinse jeans and a light blue button-down shirt, over which he wore a black blazer

All about family: The 75-year-old musician has long been known to be a devoted family man

Quirky style: Photographer Mary stepped out in a black jacket, teamed with patterned trousers

Glamorous: Mary highlighted her good lights with a light dusting of natural-hued makeup

Black to basics: Arthur opted for a black ensemble, which included a blazer, polo top and jeans

High spirits: Sir Paul was upbeat as he left Lulu's Member's Club in Mayfair later that night

Main man: The Beatles legend was his usual cheerful self as he prepped for the journey home

And his famous grandfather was on hand to help settle him in on the sprawling New Haven, Connecticut, campus - with students excitedly tweeting about spotting the legendary musician in their midst as he strolled the grounds with the teen.

Mary is Sir Paul's eldest biological child with his late wife Linda Eastman, who he was married to from 1969 until she died of breast cancer at age 56 in 1998.

The rocker adopted Linda's daughter from her first marriage Heather, 54, and the couple raised three biological children together: Mary, 48, Stella, 46, and James, 40.

Pretty in pink: Style icon Twiggy, 68, caught the eye in a pink blazer, which perfectly matched her bright suede brogues and was teamed with a pair of grey trousers

Shades: Complementing her ensemble with a delicate pendant, she also wore stylish shades

Hitting all the right notes: The Eurovision Song Contest's first ever British winner Sandie Shaw was also on hand for the event, as was director David Batty

The cold shoulder: Denise Welch hit the red carpet in a black outfit with a cold shoulder top

Hubby: She beamed as she posed alongside Lincoln Townley, her husband of almost five years

Pals: Paul and Sir Michael Caine looked to be in great spirits as they posed together for a snap

All is well! Paul couldn't resist flashing a thumbs up as he stood out the venue

Having fun: Paul looked windswept as he mingled with others

He went onto marry Heather Mills in 2002 but the former flames, who share daughter Beatrice Milly, separated in 2006 and they were divorced in March 2008.

In 2007, he began dating American beauty Nancy Shevell, going on to tie the knot with her at London's Old Marylebone Town Hall in October 2011.

Going strong with their romance, Paul gushed about his wife during an episode of Australia's 60 Minutes in June 2017.

'She's a party girl. She's a music fan,' he said. 'She actually came to see me a while ago, when I was playing quite Madison Square Garden.'

In his element: He couldn't resist putting on an animated display

What are you saying? Paul enjoyed a hearty chatter

Good day: The smiles continued as he was driven home

Famous: Dr DRE was swarmed by fans who wanted his autograph

Sweet: Ava Phillippe looked the spitting image of famous mother Reese Witherspoon as she stepped out with Sir Paul McCartney's grandson for a night out in Mayfair on Monday

On Sunday evening Sir Psul's grandson was joined by Reese Witherspoon's daughter Ava Phillippe, 18, as they strolled through Mayfair before heading to celeb hotspot Sketch together.

Arthur was casually-clad in a grey zip-up jumper, black skinny jeans and white trainers.

Meanwhile Ava showed off her sartorial flair in a navy tartan coat which skimmed over her svelte figure.

Sartorially savvy: The socialite paired the look with a casual white t-shirt, black bootcut jeans and added a boost to her height with black boots

Trend-setter: Ava showed off her sartorial flair in a navy tartan coat which skimmed over her svelte figure