Empress Masako of Japan - who was dubbed 'a broken butterfly ...

Empress Masako, a talented economist who became only the third commoner to marry into the royal family, has long been seen as Japan's 'reluctant royal'. 

Although she has stepped up her role since her husband Emperor Naruhito ascended the throne in 2019, Masako is known to still suffer with ill-health - the product of a difficult and complicated relationship with royal life. 

The Japanese royals touched down in the UK on Saturday and yesterday commenced a busy schedule of engagements for the royal state visit. 

King Charles and Prince William have rolled out the red carpet for the couple with a series of extravagant celebrations, concluding with a lavish state banquet on Tuesday evening. 

But after a hectic first day, Empress Masako, is now set to take some time away from the spotlight and won't attend today's engagements after a rest day was built into the schedule for her. 

Behind the scenes her role as Empress has always been a complicated one, beset by health issues and struggles to adapt in an imperial household that does not allow women to take the throne or continue royal duties if they marry a commoner. 

Dubbed by the Japanese press as a 'broken butterfly' and compared to Princess Diana, Masako struggled to adapt to royal life after her marriage and has spent periods away from the public eye - the longest of these being 11 years. 

Now, the state schedule for Wednesday will see the Emperor attend engagements alone. 

In advance of the trip, doctors had warned that Masako would likely need to sit out some of the activities to preserve her energy - as she has done frequently through the course of her marriage - so the decision should come as no surprise. 

The Empress is not set to attend tonight's banquet at the Guildhall hosted by the Lord Mayor and City of London corporation. 

Naruhito will be joined by the Duke and Duchess of Edinburgh and is expected to make a speech - despite his wife not being by his side.  

The Emperor will also visit the Francis Crick Institute, which supports a research partnership between the UK and Japan, including health issues such as cancer, vaccines and the role of genetics in infectious diseases. 

But on Thursday, onlookers can expect to see Masako back in action for a formal farewell to the King and Queen at Buckingham Palace and visit to the young V&A. 

Naruhito will once again be alone for a private visit to St. George's Chapel in Windsor to lay a wreath on the tomb of Queen Elizabeth II, and a visit to Kew Gardens.  

The first day of the royal state visit on Tuesday captured the nation's attention with a glittering ceremonial welcome of pomp and pageantry. 

The much anticipated trip had been postponed from 2020 - and was nearly missed again due to concerns over the timing of the general election.  

Naruhito and Masako were treated to a day of splendour, having a private lunch before attending a viewing of items from the Royal Collection.  

They joined a traditional procession, in which the Empress wore a white facemask in the carriage with Queen Camilla due to a horse hair allergy. 

In the evening, Charles and Camilla threw a lavish State Banquet for the Emperor and Empress at Buckingham Palace, attended by Rishi Sunak and Sir Keir Starmer, as well as leader of the Liberal Democrats Sir Ed Davey. 

There, Camilla showed off the King's new Family Order for the first time – painted on plastic instead of ivory. The tradition, which dates back to the 19th century, normally features a portrait of the monarch surrounded by diamonds and suspended from a silk bow. 

With a degree in economics from Harvard, the ability to speak five languages and a background in diplomacy, Empress Masako is arguably one of the most accomplished royal consorts in the world.

As a young girl, she grew up spending time between Moscow and Boston, the daughter of Hisashi Owada, a senior diplomat and former president of the International Court of Justice. 

The Empress inherited her father's brains and talent for diplomacy, going on to study economics at Harvard and being only one of three women in her cohort to pass the prestigious Japanese Ministry Of Foreign Affairs entrance exam. 

The accomplished young woman picked up hobbies such as piano, tennis, handicrafts, and learned five languages, including English, French and German. 

Her promise was clear after she studied law at the University of Tokyo and even used her diplomatic skill to resolve trade disputes between Japan and the US.   

The talented economist first met her future husband aged 22 at a tea for the Infanta Elena of Spain in 1986. 

They both studied at Oxford University and Naruhito, impressed by her brains and beauty, was instantly captivated. 

He instantly pursued her and the couple were dogged by the press throughout their early courtship. 

But Masako had never expected to enter royal life and, with a promising career ahead of her, was reluctant to give up her freedoms to marry him. 

Naruhito, however, refused to give up and proposed marriage three times - twice receiving a refusal. 

She eventually relented after he said becoming a princess would allow her to stay involved in diplomacy, and accepted the third proposal on her birthday in 1992. 

The couple married 1993 at Imperial Shinto Hall in Tokyo with 800 guests, making Masako the second 'commoner' to marry the first in line to the throne and the third to marry into the royal family at all. 

Speaking at a press conference after their wedding, she said: 'His Highness told me that you may have many worries and anxieties about entering the imperial house, but I will do everything in my power to protect you as long as I live.' 

The marriage was seen as controversial and was not approved by the Imperial household, due to the connection of Masako's grandfather to the Minamata scandal, when the dumping of chemical plastics led to the spread of disease. 

For unexplained reasons, Masako did not complete her thesis before returning to Japan and it has not been plain sailing for her or the imperial family since. 

From the start, Masako found life in the Imperial court a 'difficult adjustment' and she was labelled a 'broken butterfly' by the Japanese press. 

For this reason, she has been compared to Britain's Princess Diana over the years, due to their shared struggle to adapt to the scrutiny of life in the royal spotlight.  

The now royal was diagnosed with 'adjustment disorder' in the early 2000s and was said to be suffering from depression and anxiety, which eventually forced her to spend periods of time away from public life. 

In a press conference in 2004, the Prince Hiro said she seemed 'exhausted' from royal life and the effort of trying to fit in, later urging for the public to 'watch over her kindly'. 

The pressure to produce a male heir has been blamed for a stress-related illness that has led to her periodic absences - once for 11 years - from public life. 

Japan's strict laws of succession forbid women from ascending to the Chrysanthemum Throne and force them to give up their titles if they marry commoners. 

Masako first conceived in 1999 but suffered a miscarriage after announcing the pregnancy. 

The couple eventually welcomed a daughter, Princess Aiko in 2001, following fertility treatment - who remains the couple's only child.

Her birth fuelled a succession debate about whether to allow women to rule as Aiko is not allowed to ascend the throne. Instead, Naruhito's brother Crown Prince Fumihito, 58, is set to inherit the title.  

According to a recent poll, 90 per cent of the public support a change to the law to allow women to ascend the throne, according to a recent poll. 

But conservative members of the ruling Liberal Democratic Party oppose the changes and they are yet to be instated. 

Since her husband ascended the throne in 2019 following Akihito's abdication, Masako has taken on a more public role and has even accompanied her husband on a visit to the US to meet Donald Trump. 

Masako and Naruhito attended the funeral of Queen Elizabeth II in 2022, their first visit abroad since becoming rulers. 

The Empress is still in the process of recovering from a stress-induced illness, despite increasing her numbers of engagements. 

Her doctors have said she is not fully recovered and Masako, like Queen Camilla, still struggles at times with foreign travel.

Japan's monarchy, like Britain's, has faced turmoil in recent years and is grappling with running as a slimmed-down entity.

The immediate succession crisis was resolved in 2006 when the Emperor's younger brother and heir, Fumihito, now 58, had a son, Hisahito, in 2006.

But there is still a shortage of males and the women in the family lose their royal status when they marry commoners.

In 2021, Fumihito's daughter Mako became the latest in a succession of princesses to lose her title when she wed a commoner.

It has led to a shortage of working royals in Japan.

Craig Prescott, a constitutional expert at Royal Holloway, University of London, believes there is much for both monarchs to compare and contrast this week.

'I think they are both grappling with, in a sense, the weight of history,' he said.

Before becoming empress, the then Princess Masako said she felt 'insecure' about ascending the throne in 2018. 

She questioned 'how helpful I will be' when she took over the role but vowed to devote herself 'to the happiness of the people'. 

In a statement she said: 'Even though I feel insecure about how helpful I will be when I think about the days ahead... I want to devote myself to the happiness of the people so I will make an effort to that end.' 

Referencing her illness, Masako said: 'I am delighted at the fact that I can perform more duties than before as I have tried to improve my physical condition.' 

But her doctors warned in a separate statement that it is important for the crown princess to continue treatment as she remains vulnerable to fatigue, especially after a large ceremony or successive duties.