The Sussexes had already faced a turbulent year amid the fall-out from Megxit and other controversies.
Harry and Meghan quit as senior working royals in March and moved to the US, just as the coronavirus pandemic took hold around the world and the nation entered lockdown.
Now the couple are grieving the loss of their second child, after Meghan suffered a miscarriage in the summer.
As the duchess shared her experience in The New York Times, she wrote: “This year has brought so many of us to our breaking points. Loss and pain have plagued every one of us in 2020.”
The article appeared just one day before Thanksgiving – the couple’s first since they stepped down from royal duties.
Meghan wrote: “So this Thanksgiving, as we plan for a holiday unlike any before — many of us separated from our loved ones, alone, sick, scared, divided and perhaps struggling to find something, anything, to be grateful for — let us commit to asking others, ‘Are you OK?'”.
Harry and Meghan sparked a major royal crisis in January by publicly announcing their plans to stop being senior royals in a bombshell statement.
They wanted a dual role, earning their own money and supporting the Queen, but the plan was unworkable, and would have led to accusations they were profiting from the monarchy.
Faced with a hard Megxit, it was decided the couple should end their time as working royals completely, and stop using their HRH styles.
They have since settled into a new life in Montecito in California, bought an £11 million house and secured a lucrative deal with streaming giant Netflix, rumoured to be worth more than £150 million.
They have also been working on their Archewell charitable foundation and been seen volunteering during the Covid-19 crisis, but controversy has not been far away.
Harry was accused of political interference after he urged people in the US to “reject hate speech” and vote in the presidential election.
Prince Harry poking his woke nose into the US election & effectively telling Americans to vote against President Trump is completely unacceptable behaviour for a member of the Royal Family.
— Piers Morgan (@piersmorgan) September 23, 2020
Earlier this month, the duke – a former serviceman – was left saddened when he was denied his wish for a wreath to be left on his behalf at the Cenotaph on Remembrance Sunday.
The Sussexes paid a private visit to Los Angeles National Cemetery instead, but were accused of staging a publicity stunt after they were photographed there by Lee Morgan, who specialises in fashion and celebrity portraits.
In August, a new biography of the couple, Finding Freedom, revisited the rift between Harry and his brother the Duke of Cambridge.
The book by Omid Scobie and Carolyn Durand said Harry was angered by what he perceived as his brother’s “snobbish” attitude to his bride ahead of his wedding after William advised him “take as much time as you need to get to know this girl”.
Following the Queen’s Sandringham summit in January, which was called to solve the Megxit debacle, William and Harry stopped speaking for two months, Scobie said.
The Duchess of Cambridge was also accused of not reaching out to Meghan to help her settle into royal life and of snubbing her sister-in-law at the Sussexes’ final public royal engagement.
The Sussexes denied they had any involvement with the book, but it emerged in High Court documents last week that Meghan allowed an unnamed individual to speak to the authors to prevent “further misinformation” being spread about her relationship with her estranged father.
Meghan is suing Associated Newspapers Ltd (ANL), publisher of the Mail on Sunday and MailOnline, over an article which reproduced parts of the handwritten letter sent to her father Thomas Markle in August 2018.
Legal papers also showed last week that Meghan turned to two unnamed senior royals for help, and they advised her to write the letter to Mr Markle.
Meghan’s miscarriage took place in July – the same month that the duchess was battling to prevent Associated Newspapers from naming five friends who spoke anonymously to the US magazine People to defend her from tabloid “bullying”.
In October, the full trial over the letter was postponed from January 2021 to next autumn for a confidential reason, after a private hearing.
Harry also has an ongoing legal action. He has brought cases against News Group Newspapers and Mirror Group Newspapers over alleged historical phone hacking.
Meanwhile, the couple sought to deal with outcry caused when taxpayers footed the £2.4 million bill for the renovation of their Windsor property Frogmore Cottage.
Harry and Meghan, who only lived in the house for a short while, have this year paid an undisclosed sum upfront for the rental and refurbishment of the period property.
But, while they retain the home, they have handed the keys to Harry’s cousin Princess Eugenie and her husband Jack Brooksbank, who are expecting their first child next year and moved in as part of a private agreement.