Kate Middleton wows in an identical dress to one worn by Princess Mary of Denmark

They were dubbed unofficial ‘royal sisters’ by the late Chanel designer Karl Lagerfeld thanks to their strikingly similar appearance and comparable taste in fashion.

So it’s perhaps no surprise that the Duchess of Cambridge appeared to take style cues from Denmark’s Princess Mary again this week – with Kate, 38, sporting a deep blue £525 Beulah London gown first spotted on the Australian-born royal last year.

Joining her husband Prince William, 38, on a visit to the Queen Elizabeth Hospital in King’s Lynn, near their Norfolk home of Anmer Hall, on Sunday to mark the 72nd anniversary of the NHS, Kate teamed the outfit with matching heels and drop earrings.

Meanwhile, Mary paired cream heels and hooped earrings with the shirt dress – which features a striking white collar and blue polka dot pattern – during her trip to Indonesia in December. 

It’s not the first time Mary and Kate have shared styling tips, with royal fans often pointing out how similar the two future Queens appear.

From their attire on the slopes to how they dress during public engagements and for official state visits, here, FEMAIL reveals the times the royals proved they are long lost style sisters… 

Striking patterned frocks

The £525 blue gown was previously worn by Princess Mary of Denmark during a visit to Indonesia last December

It’s perhaps no surprise that the Duchess of Cambridge appeared to take style cues from Denmark’s Princess Mary again this week – with Kate (pictured left), 38, sporting a deep blue £525 Beulah London gown first spotted on the Australian-born royal (seen right) last year

The women are not only a fan of identical polka dot looks, but have also previously been seen stepping out in similar sheer floral designs. Pictured: Mary in 2014

Kate pictured in 2016 in a similar design to Mary's floral pattern

The women are not only a fan of identical polka dot looks, but have also previously been seen stepping out in similar sheer floral designs. Pictured: Mary, left in 2014, and Kate, right in 2016

Both Kate and Mary appear to be fan favourites of patterned frocks, with the royals often sporting the look during public engagements. 

Kate’s £525 Beulah London gown in blue – a preferred colour of the fashion-forward duchess – was the same style as the red number she wore for a minute-long mental health message released in May.

The duchess teamed her dress – which featured an eye-catching large white collar – with matching blue heels and opted for a pulled back hairdo, as well as £800 diamond and yellow gold earrings by designer Patrick Mavros for the visit. 

Beulah London, co-founded by Lady Natasha Rufus Isaacs and Lavinia Brennan in 2010, has become a go-to label for Kate, who has stepped out in the designs on a number of occasions.

And the frock also appeared to be a favourite of Mary’s, with the princess sporting the stylish garment in December last year during a trip to Indonesia.

She added a pop of extra colour by pairing the shirt dress with cream heels and elegant hooped earrings. 

Elegant headbands

Kate at the christening of Meghan Markle and Prince Harry's son Archie

In December 2019, Mary (pictured ) drew inspiration from the duchess by wearing a style of headband beloved by the British royal

In December 2019, Mary (pictured right) drew inspiration from the duchess (pictured left in July 2019) by wearing a style of headband beloved by the British royal

Kate also wore a £34 'hatband' from Zara for an annual concert honouring those who died in the First World War at the Royal Albert Hall (pictured at the event on November 9)

Kate also wore a £34 ‘hatband’ from Zara for an annual concert honouring those who died in the First World War at the Royal Albert Hall (pictured at the event on November 9)

In December 2019, Mary drew inspiration from the duchess by wearing a style of headband beloved by the British royal.  

Mary donned a sequined burgundy ‘hatband’ from Jane Taylor London for the opening of a new emergency unit at the Viborg Regional Hospital, north west of Copenhagen.

The mother-of-four, who was born in Hobart, Tasmania, oozed regal glamour in a burgundy blouse and high-waisted grey midi-skirt, adding height with a pair of burgundy point-toe stilettos. 

The ‘hatband’ – a trendy accessory which mixes elements of a hat and headband – is regularly seen on Kate, who wore a quirky velvet plaited design to the christening of Prince Harry and Meghan Markle’s son, Archie Harrison, in July that year.

Kate also stepped out in a £34 black jewelled headband from fast fashion label Zara for an annual concert honouring those who died in the First World War at the Royal Albert Hall on November 9, 2019. 

Tartan skirts and coats

The Duchess of Cambridge has repeatedly showcased her love of tartan, plumping for her favourite Alexander McQueen coat while in Scotland in January (pictured)

While the royals also embrace different patterns, there is one fashion look that both appear to love - with Mary (pictured above in 2019) and the duchess proving to be fans of tartan

While the royals also embrace different patterns, there is one fashion look that both appear to love – with Mary (seen right in 2019) and the duchess (pictured left in the same year) proving to be fans of tartan

Kate sported a £1,500 red skirt (above) over the Christmas period by Emilia Wickstead

A day before the duchess' festive look, Mary wore a £1,295 tweed midi skirt by Alexander McQueen (above)

Kate sported a £1,500 red skirt (pictured left) over the Christmas period in 2019 by Emilia Wickstead. A day before the duchess’ festive look, Mary wore a £1,295 tweed midi skirt by Alexander McQueen (pictured right)

While the royals also embrace different patterns, there is one fashion look that both appear to love – with Mary and the duchess proving to be fans of tartan. 

In March 2019, Mary was the latest royal to wear a green tartan coat on tour in Texas, after both Kate and Meghan Markle wore similar styles in Scotland.

The Danish royal wore a green and black tartan coat by Baum und Pferdgarten, which she paired with a black jumper and trousers to beat the European March chill.

Princess Mary completed her outfit with a long chain, as she travelled around Texas while promoting Danish culture and sustainable living. 

Meanwhile, Kate has repeatedly showcased her love of tartan, plumping both for her favourite Alexander McQueen coat while in Scotland in January last year and a £1,500 red skirt over the Christmas period in 2019 by Emilia Wickstead. 

A day before the duchess’ festive look, Mary wore a £1,295 tweed midi skirt by Alexander McQueen when she attended an event marking International Disability Day in Copenhagen. 

Eye-catching colourful dresses

The Duchess of Cambridge (pictured) drew plaudits for her red Jenny Packham dress when she attended her very first state banquet in 2015 and clinked glasses with the Chinese president

Just the following year, Princess Mary (pictured) also opted for regal red and a tiara when she clinked glasses with the late Prince Henrik at a State Banquet at Fredensborg Palace

The Duchess of Cambridge (pictured left) drew plaudits for her red Jenny Packham dress when she attended her very first state banquet in 2015 and clinked glasses with the Chinese president. Just the following year, Princess Mary (seen right) also opted for regal red

The pair have both favoured a block colour on occasion (pictured), such as royal blue (Kate Middleton pictured in 2016

Princess Mary pictured in 2017, wearing a very similar dress

The pair have both favoured a block colour on occasion (pictured), such as royal blue (Kate Middleton pictured in 2016; Princess Mary pictured in 2017)

The duo are both fans of colour-rich clothing as they have often been seen wearing bright reds, blues and oranges.

Another example was when the duo appeared surprisingly similar in a block blue frock, featuring mid-length sleeves and a high round-neck. Kate sported the look in 2016, while Mary treated fans to the outfit in 2017.

They also matching when each attending a more formal setting, with both favouring colour-block red gowns to complement their glittering tiaras in previous years.

The Duchess of Cambridge drew plaudits for her red Jenny Packham dress when she attended her very first state banquet in 2015 and clinked glasses with the Chinese president.

Just the following year, Princess Mary also opted for regal red and a tiara when she clinked glasses with the late Prince Henrik at a State Banquet at Fredensborg Palace.

As important faces of two royal families the pair always turn up to events looking sophisticated and stylish. 

They often opt for high neck dresses with modest sleeves and knee length skirts and both are thrifty with their wardrobes, as they are seen recycling outfits. 

Read more at DailyMail.co.uk