The Sydney Opera House, the Sydney Harbour Bridge, indeed Sydney Harbour and even the sun put their best feet forward when the Duke and Duchess of Cambridge arrived in town.

They had back-ups too: There were also dancing Aborigines, two Test cricketers, a cricket bat for Prince George with an Aboriginal goanna motif and thousands of Australians, young and old, lining Bennelong Point waving Australian and Union Jack flags, flowers and signs - such as ''I was born the same day as Prince George'' waiting for the first public appearance.

NSW Governor Marie Bashir said it all when welcoming the royal couple to a reception in the Opera House's northern foyer.

It was, she said, her eyes sweeping the building, ''the site of the first British settlement which heralded the first expectations of modern Australia''.

The prince acknowledged he was rather impressed by Sydney.

''This visit to Australia has been one that Catherine and I have been looking forward to for a long time,'' he told a reception at the Opera House. ''On my first visit here as an adult in 2010, I remember just how bowled over I was by Sydney: seeing the energy and diversity of this beautiful city, and understanding just how much Australia is the home of innovation, opportunity and possibility.''

The royal couple arrived in Sydney on a day of high political drama but the Opera House was a hermetically sealed world.

The then premier Barry O'Farrell - and wife Rosemary - had been slated to greet the royal couple.

But five hours earlier, Mr O'Farrell fell on his sword amid revelations at ICAC and he was airbrushed into regal oblivion. President of the Legislative Council Don Harwin stepped into his shoes.

The royal couple arrived at Sydney Airport from New Zealand soon after 2pm but Prince George did not accompany his parents to the opera house reception.

Nevertheless he was there in spirit: His father feared his first word might be bilby, ''only because koala is harder to say''.

Up to 400 guests attended the welcome reception in the opera house's northern foyer. They were mainly young leaders close to the ages of the royal couple.

The royals were introduced to a selected group of young leaders, including Young Australian of the Year Jacqueline Freney, a para-Olympian swimmer.

''The princess spoke about watching the swimming at the London Games. I was just knocked out,'' the 21-year-old Canberran said.

After about an hour they left the reception, pausing briefly for a photo opportunity with the Cricket World Cup 2015 trophy and chatted briefly with former Australian cricketer Glenn McGrath and Australian women's cricketer Ellyse Perry, and children dressed to represent the 14 nations in the event.

Then it was the Australian public's turn. Thousands gathered from 8am to catch a glimpse of the royal couple on Australian soil.

The rain of the last few days had cleared with blue skies and full sun greeting the visitors. With school holidays in full swing, children were everywhere and many office and construction workers had left work early to join the crowd.

The prince and princess slowly made their way down the long the parapet, accepting flowers and posing for photos until reaching the Man O' War steps where they were farewelled by the Governor, her husband Sir Nicholas Shehadie, and Mr Harwin. They boarded a police launch for the ride across the harbour to Admiralty House wharf.