Kevin Rudd has been officially sworn in as Australia's 26th Prime Minister in a ceremony at Government House this morning.
In a brief ceremony, Governor-General Michael Jeffrey invited Mr Rudd to take the executive oath, while his deputy, Julia Gillard, swore an affirmation.
The ceremony was attended by Mr Rudd's wife Therese Rein, and his children. Ms Gillard's partner, Tim Mathieson and her sister Alison looked on.
The formalities, which took place with Mr Rudd holding a copy of the Bible, formally ended former Liberal leader John Howard's 11-and-a-half-year stint as Prime Minister.
"I must ... formally ask you for your assurance that you have been elected leader of the party holding the majority of seats in the House of Representatives, that you can form a government and that you will have confidence of the House of Representatives,'' Major-General Jeffery said.
Mr Rudd replied: "Your Excellency I'm pleased to advise you that we have such a position and provide you with that assurance.''
Major-General Jeffery: "In that case I'll now accept the resignation of the Honourable Prime Minister John Howard which has the effect of terminating all the appointments of the former Government.
"By the powers conferred on me by the constitution, I'm therefore pleased to swear you in as Australia's 26th Prime Minister."
The swearing of the two Government leaders was followed by the swearing in of the rest of the ministry.
The incoming ministers swore oaths and affirmations as members of the executive council.
About half the ministry, including Treasurer Wayne Swan, Senate leader Chris Evans, Finance Minister Lindsay Tanner and Foreign Minister Stephen Smith, opted for affirmations.
This afternoon, Mr Rudd will hold a full ministry meeting, as the Government prepares for a vigorous start to its work.
The new Prime Minister wants to get preparation under way in the key areas of industrial relations and education before Christmas.
Interim legislation on industrial relations will be introduced as soon as the new Parliament commences in early February.
Later this week, the cabinet will meet in Mr Rudd's home town of Brisbane.
He has promised to take the cabinet regularly out of Canberra.
Earlier, Prime Minister Rudd described it as just another day's work.
Mr Rudd, who led Labor to its first federal electoral victory in 11-and-a-half years on November 24, said today was an important day.
Kevin Rudd, current Australian Labor Party leader, was sworn in today as Prime Minister of Australia by Governor-General Michael Jeffrey. Rudd has become the 26th Prime Minister since Australia's federation in 1901.

Former Prime Minister John Howard and the Liberal Party and Coalition were beaten in the 2007 election which took place last month, by the Australian Labor Party who managed to gain the extra 16 seats they needed to have a majority in the House of Representatives. Mr Howard lost his seat that he held for 33 years, 11 as Prime Minister, to Labor candidate Maxine McKew.

Mr Rudd was sworn in at a small ceremony at Government House by Mr Jeffrey, alongside Deputy Prime Minister Julia Gillard, who was also sworn in today. Mr Rudd's wife, Therese Rein and his three children were also present at the ceremony.

Later that afternoon, Mr Rudd plans to hold a full meeting which all of his newly-sworn-in ministers will attend. In late November, Mr Rudd requested that all his ministers attend a visit at two schools in their local electorate before meeting for a caucus meeting on November 30.