THE Duke and Duchess of Sussex are expecting a baby in spring 2019, Kensington Palace has announced.

The newly-wed couple arrived in Sydney on Monday ahead of a 16-day tour which will take in Australia, New Zealand, Fiji and Tonga.

In a statement, Kensington Palace said: "Their Royal Highnesses The Duke and Duchess of Sussex are very pleased to announce that The Duchess of Sussex is expecting a baby in the Spring of 2019.

"Their Royal Highnesses have appreciated all of the support they have received from people around the world since their wedding in May and are delighted to be able to share this happy news with the public."

Harry and Meghan were wed at Windsor Castle in May and the news was announced on the eve of their first tour outside the UK and Ireland.

The Queen, the Duke of Edinburgh, the Prince of Wales, the Duchess of Cornwall and Duke and Duchess of Cambridge are said to be "delighted" for the couple.

HARRY AND MEGAN'S DREAM OF STARTING A FAMILY

THE Duchess of Sussex once described motherhood as being on her "bucket list", while the Duke of Sussex has often confessed he would love to have children.

The former actress's pregnancy fulfils the pair's long-held ambition to become parents.

In the run-up to their wedding, Meghan hinted at starting her own brood with Harry.

On a trip to Belfast less than two months before the big day, the bride-to-be joked when she was shown an innovative range for newborns: "I'm sure at some point we'll need the whole (lot)."

In an interview in 2016, Meghan said becoming a mother was on her "bucket list".

"I can't wait to start a family, but in due time," she said.

The topic cropped up in the couple's engagement interview, with Harry speaking of their plans.

"You know, I think one step at a time, and hopefully we'll start a family in the near future," he said.

Harry has long since admitted he would love to have children.

Back in 2015 before he met and fell in love with Meghan, he revealed that seeing his brother's family continue to grow made him wish he had some of his own.

"Of course I would love to have kids right now but there's a process that one has to go through and tours like this are great fun," Harry said.

"Hopefully I'm doing all right by myself. It would be great to have someone else next to me to share the pressure, but you know, time will come and whatever happens, happens."

THE LOW-DOWN ON THE DUKE AND DUCHESS' FIRST CHILD

Where will the baby fall in the line of succession?

Seventh in line. The baby will bump Harry's uncle the Duke of York into eighth place in the line of succession.

Princesses Beatrice and Eugenie move into ninth and 10th place, and the Earl of Wessex - the Queen's youngest son - drops out of the top 10 for the first time to 11th in line.

How will the baby be related to the Queen?

The baby will be a great-grandchild of the Queen and the Duke of Edinburgh, and the Prince of Wales's grandchild and the Duke and Duchess of Cambridge's niece or nephew.

Will he or she ever be monarch?

Unlikely. The baby will have three cousins Prince George - a future king - and Princess Charlotte and Prince Louis, who are further up the line of succession, so it is a safe bet that throne will stay on the Cambridge side of the family.

What will the baby be called?

William and Kate chose royal favourites for their children.

But will Harry and American-born Meghan go classic or break the royal mould when naming their baby?

If they stay traditional, something like Alice, Mary, Elizabeth or Victoria for a girl, and James, Philip, Frederick or Arthur for a boy are possibilities.

In the US, the most popular name for a baby girl is Emma and Liam for a baby boy.

Will the baby be a prince or princess?

No they will not be a prince nor a princess, nor an HRH because George V limited titles within the Royal Family in 1917.

So what will their title be?

A son would be known as Earl of Dumbarton - because a first son of a duke is allowed to use one of his father's other lesser titles as a courtesy title.

Harry was also made the Earl of Dumbarton on the morning of his wedding, as well as being given a dukedom.

A daughter would be Lady (first name) Mountbatten-Windsor.

But the Queen could change this?

Yes. The Queen stepped in ahead of George's birth to issue a Letters Patent to ensure the Cambridges' children had fitting titles, but this royal baby is much further down the line of succession.

When and where will the baby be born?

Kate had three successful deliveries at the private Lindo Wing in St Mary's Hospital, Paddington, so Meghan might follow her sister-in-law's lead.

Harry was also born there in 1984. It is close to Kensington Palace and well practiced at dealing with royal births, and the publicity surrounding them.

Will the baby have dual citizenship?

Harry and Meghan could apply for their child to have dual US-UK citizenship.

Meghan is planning to become a British citizen - but it is not known whether she will hold dual nationality, and at present is still a US citizen.

According to the American Embassy in the UK, a child born outside of the US and in wedlock to a US citizen parent and a non US citizen parent, may acquire US citizenship at birth if the US parent lived in America for five years - two of which were after the age of 14.