Harry and Meghan were wed at the same chapel in another impressive wedding in May, and their news emerged as their first tour outside the UK and Ireland begins.

The couple arrived in Sydney yesterday ahead of their hotly-anticipated 16-day tour which will take in Australia, New Zealand, Fiji and Tonga.

Prince Harry and his wife Meghan, Duke and Duchess of Sussex, arrive in Sydney yesterday. Photo / AP

Eugenie's star-studded two-day event garnered huge media attention, but many have questioned whether the minor royal's occasion warranted such extravagance.

It is thought royal aides were concerned about public reaction to the extravagant celebrations, which cost the taxpayer £2 million ($4m), and suggested toning it down.

Palace sources said it was the Duke of York who insisted his daughter take a carriage ride through Windsor, mimicking Harry and Meghan earlier this year.

Speaking ahead of Eugenie's wedding last Friday, her father Prince Andrew, Duke of York, talked about how it would be very different to Harry and Meghan's big day.

He told ITV's This Morning: "It will not be the same as the previous one that was held in May. It's not a public wedding, this is meant to be a family wedding.

"There will be a few more people than most people have. There are a few more than Harry had but that's just the nature of Eugenie and Jack.

"They've got so many friends and they need a church of that size to fit them all in."

Minor royal weddings in the past have been short and held in private - a stark contrast to celebrations over the weekend.

Among them was when Princess Margaret's daughter Lady Sarah Armstrong-Jones, the Queen's niece, tied the knot to Daniel Chatto in 1994.

Their service at St Stephen Walbrook Church in the City of London lasted just 30 minutes and 200 guests were invited. But Eugenie handed out 1,400 invitations.

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 Harry and Meghan.

Prince Harry and Meghan, Duchess of Sussex, talk with Princess Anne, at the wedding of Princess Eugenie of York and Jack Brooksbank on Friday. Photo / AP

Doria Ragland, the mother of the duchess, is "very happy about this lovely news" and "looks forward to welcoming her first grandchild".

A Kensington Palace spokesman 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."

The baby is expected to arrive in Spring 2019. Photo / Getty Images

Last Friday, Eugenie shared two shy kisses on the West Steps of St George's Chapel with her new husband Jack after their lavish royal wedding ceremony.

The couple tentatively performed the kisses for the cameras on the steps, which were decorated with masses of autumn flowers and lined with Grenadier Guards.

After their afternoon reception in Windsor Castle, Jack drove Eugenie away in a silver DB10 Aston Martin sports car. The wedding drew in a peak of 3.9 million on ITV.