Both are tall and elegant. Both were middle-class commoners when they married into their respective royal families.
So, perhaps comparisons between Queen Mary of Denmark and our own Princess of Wales were inevitable.
There is more to it than that, however. Both women have a carefully considered approach to style, working within the tight constraints of what is expected from a royal.
Mary and Catherine have a shared appreciation, too, of ethical brands and of British designers in particular.
According to the late Karl Lagerfeld, the design guru at the helm of Chanel for many years, Australian-born Mary could even have been consideredKate Middleton's'big sister' in fashion terms.
Here we take a look at the style siblings through the years - and how Queen Mary, who came to the Danish throne earlier this year, has so often been one step ahead...
Beulah London
One step ahead: Queen Mary wore Beulah London's 'Ahana' dress a year before Kate Middleton showcased the design
Beulah London's 'Yahvi' dress is also a hit with the royals (pictured left: Sophie, the duch*ess of Edinburgh; right: Queen Mary)
Mary stepped out in a geo print shirt dress in 2019; Kate copied the look in 2020
Mary, who been vocal about her commitment to sustainability, has also worn a berry velvet dress while Sophie favours the coral version
Since embarking on a volunteer trip to India and witnessing the harsh reality of modern slavery, Beulah London founders Natasha and Lavinia have been dedicated to empowering vulnerable women through the fashion industry.
Their initiative has gained attention in royal fashion circles.
Queen Mary and the Princess of Wales have both been spotted wearing the brand's 'Yahvi' dress in olive, while Sophie, duch*ess of Edinburgh, owns versions in cream and coral.
One step ahead, Mary debuted the 'Shalini' geo print shirt dress in 2019, with Kate emulating the look in 2020.
Similarly, the Danish royal was seen in Beulah London's cream 'Ahana' dress a year before Kate Middleton sported the blush variation.
Mary has been vocal about her commitment to sustainability. She is patron of theGlobal Fashion Agenda and the Copenhagen Fashion Summit,initiatives dedicated to creating community and carbon-neutrality within the fashion industry.
'We haven't seen ethical consumers penetrate mainstream fashion in the same way we've observed other areas and this is partially because consumers have a very irrational buying pattern,' the royal told Hola!
'When we buy clothes, it is often associated with feelings, joy, dreams and passion -and deeply linked to our identity.'
'I keep clothes that I think my daughters will inherit one day. Other clothes are passed on to people who can benefit from them.'
It's highly likely that the Queen will hand down her gorgeous collection of dresses to her daughters, Princesses Isabella and Josephine.
The Fold
In April, Mary showcased a distinctive cobalt suit, incorporating The Fold's signature asymmetric wrap detailing
The monarch's forest green 'Finchley' coat was previously spotted on Pippa Middleton (right)
The Fold's Harrow blouse, pictured on Mary in March, offers another effortless take on tailoring
Mary's fascination with The Fold's expert tailoring comes as no surprise.
Established in 2012 by Polly McMaster, the British womenswear label has a mission 'to empower women to achieve their ambitions'.
The brand boasts a plethora of celebrity endorsem*nts, with notable figures such asHolly Willoughby, Vicky McClure and Catherine, Princess of Wales, wearing its designs.
Last year, Mary joined the ranks, selecting a supremely elegant coat by the British label for a state visit from Spain.
The forest green 'Finchley' outerwear had made a previous appearance on Pippa Middleton when she attended sister Kate's Christmas carol concert in 2021.
In April, Mary showcased a distinctive cobalt suit that incorporated The Fold's signature asymmetric wrap detailing.
The vibrant hue helped the monarch make a striking solo entrance at the National Museum of Denmark.
She elevated her ensemble with Jimmy Choo court shoes and aHalberstadt necklace, featuring her husband King Frederik's initial.
The Queen has also worn the brand's 'Harrow' blouse. With its shawl collar and silk crepe de chine composition, the pieceoffers another seamless take on tailoring.
Mary paired hers with wide-leg trousers from Celine during a trip tothe University of Copenhagen in March.
Jane Taylor London
Mary wore a Jane Taylor Millinery netted fascinatorto the coronation of King Charles III and Queen Camilla
Mary has presented several outfits that are custom-made for her.
A prime example is her violet coatdress by Søren le Schmidt, worn to the coronation of King Charles III and Queen Camilla.
To complement the ensemble, Mary added a Jane Taylor Millinery netted fascinator, much to the delight of onlookers.
With a flagship on the King's Road, the brand has become synonymous with stylish headpieces. It's stunning range has been worn by a number of British royals.
Mary's bespoke halo headpiece featured a birdcage veil, creating a simple yet striking aesthetic.
Temperley London
Mary teamed her sumptuous Temperley London suit with Cenius & Bach amethyst earrings
The monarch has championed Temperley London's elegant lace dresses
The royal stunned in a silver gown for a Minister's dinner at Fredensborg Castle in 2021. She debuted the design in 2015
Queen Mary donned the Temperley London 'Trellis' gown a total of five times between 2016 and 2022.
She debuted the glamorous floor-length style at a dinner, hosted by Queen Margrethe at Christiansborg Castle, pairing it with Gianvito Rossi pumps.
Over time, Mary tailored the dress into a more practical, ankle-length silhouette, which she often teamed with a pair of golden satin pumps by Manolo Blahnik.
Temperley London, founded by Alice Temperley, is celebrated for its feminine approach to eveningwear.
Mary has also favoured the white 'Berry' dress on numerous occasions. The elegant midi is crafted from laser-cut lace, with a tie neckline and fit-and-flare silhouette.
However, in a departure from her stint of delightful dresses, the royal recently opted for a sumptuous velvet suit.
She expertly paired her tailored two-piece with Cenius & Bach amethyst earrings.
This ensemble served as a faultless accompaniment to theannual Christmas reception for the Mary Fonden at Frederick VIII's Palace.
Alexander McQueen
A standout hero in the royal's wardrobe, Mary has worn her burgundy Alexander McQueen blazer on nine occasions (pictured in January)
Mary was pictured in a skirt by the label in March. It's another favourite piece from her wardrobe, which she's worn five times
Mary chose an Alexander McQueen dress fora dinner hosted by the Embassy of Switzerland in Denmark in 2021
A standout piece in the royal's wardrobe, Mary has been seen wearing her burgundy Alexander McQueen blazer on nine occasions.
Most recently, she sported it at theLanxess Arena in Cologne for the European Men's Handball Championship final.
Crafted in Italy from McQueen's renowned leaf crepe, this jacket offers a modern take on power dressing.
The sharp silhouette features slanted flap pockets and sculptural seams that beautifully highlight the figure. It's no surprise that Mary has chosen to wear it so many times.
Last month, the royal opted for a skirt by the renowned label, another beloved piece from her wardrobe that she has worn five times.
The feminine bouclé style, with its berry and white threads, has brought a welcome splash of colour to her formal outfits.
Mary has consistently shown her loyalty to the British designer.
In 2021, she wore a Prince of Wales checked suit toUNFPA's State Of World Population Report Release at Gerlev Sports High School inSlagelse, Denmark.
A few months later, she radiated glamour in a knitted off-shoulder dress at the Swiss Embassy in Copenhagen.
Jenny Packham
Mary wore a Jenny Packham gown for her 50th birthday celebrations and the Princess of Wales followed suit
British fashion designer Jenny Packham is globally admired for her eponymous luxury brand, which graces the world's most discerning clientele.
Queen Mary's 'Georgia' dress exemplifies the label's elevated glamour and exquisite craftsmanship.
She wore the show-stopping design for her 50th birthday celebrations in 2022.
Following suit, Catherine, Princess of Wales, donned the dress at Crown Prince Hussein and Rajwa Al Saif's wedding reception, in Jordan, the following year.
However, Kate had previously worn the emerald version in 2021, possibly marking her as first to wear it.
Either way, the glinting rose gold gown was feast for the eyes on both occasions.
Emilia Wickstead
Mary showcased a beautiful fit-and-flare dress by Emilia Wickstead in 2015, followed by Kate in 2018
Emilia Wickstead is alsobeloved by Queen Mary and Catherine, Princess of Wales.
The quintessential British label, described as the 'epitome of modern femininity', was debuted by Mary in 2015.
The Danish royal opted for a graceful sky blue fit-and-flare frock during a trip to Japan.
Three years later, Kate wore the lilac version to a mental health summit in London.
While Mary may have been first to wear the dress, Kate has embraced it in cobalt, olive and teal.
Wickstead has since named the design 'The Kate' in her honour.
This, once again, underscores Mary's trendsetting nature, with the British princess following her lead.
Stella McCartney
The royal looked flawless on the red carpet in a Stella McCartney jumpsuit
She chose a Grecian-inspired Stella McCartney dress for a 2018 awards ceremony in Copenhagen
Another prominent label in Queen Mary's wardrobe is Stella McCartney.
The English fashion designer, daughter of singer-songwriter Paul McCartney, is known primarily for her fur-free and leather-free clothing.
The Australian-born Queen's admiration for the label began in 2017, when sheselected a Grecian-inspired Stella McCartney gown for the Carlsberg Foundation prize ceremony in Copenhagen.
She later wore the dress again for the 2018 Reumert Awards, held in the Schauspielhaus Zurich.
In a more recent appearance in 2022, the mother-of-four chose a pale pink jumpsuit for The Crown Prince Couple's Awards.
This tailored one-piece featured a delicate metallic mesh panel and flattering wide-leg cut, offering a worthy alternative to a traditional dress.
