Former Treasury chief Gordon Brown became the British prime minister Wednesday, promising to make the country the "global success story of the century."

British Prime Minister Gordon Brown and his wife, Sarah, stand outside No. 10 Downing Street in London on Wednesday.
(Matt Dunham/Associated Press)

"I have just accepted the invitation of Her Majesty the Queen to form a government," said Brown, who spoke to reporters outside No. 10 Downing Street alongside his wife, Sarah.

He arrived at the prime minister's official residence after a private meeting with Queen Elizabeth, who asked him to form the next government shortly after accepting the resignation of Tony Blair. Brown is the 11th prime minister the Queen has invited to lead the government under her reign.

A 56-year-old Scot known for his often stern demeanour, Brown vowed to rebuild trust in government and work to improve health care, the education system and improve affordable housing.

"At all times, I will be strong in purpose, steadfast in will, resolute in action in the service of what matters to the British people," said Brown, who is the father of two young sons.

British PMs during Queen Elizabeth's reign

Winston Churchill 1952-1955 Anthony Eden 1955-1957 Harold Macmillan 1957-1963 Alec Douglas-Home 1963-1964 Harold Wilson 1964-1970; 1974-1976 Edward Heath 1970-1974 James Callaghan 1976-1979 Margaret Thatcher 1979-1990 John Major 1990-1997 Tony Blair 1997-2007 Gordon Brown 2007-

"I want the best of chances for everyone. That is my mission — that if we can fulfil the potential and realize the talents of all our people then I'm absolutely sure that Britain can be the great global success story of this century."

The prime minister must call a national election before June 2010, with some analysts speculating voters could go to the polls as early as next summer. He will seek to head off a challenge from a revived opposition Conservative party, led by the more youthful David Cameron.

Brown has stated his top domestic priorities are improving affordable housing and overhauling Britain's National Health Service.

His devotion to fiscal "prudence" and his commitment to increasing aid to Africa are well known, but questions remain about what he intends to do about the unpopular troop deployment to Iraq and, more generally, about his foreign policy goals.

Blair has left his successor an option to call back more of the remaining 5,500 personnel by 2008.

Former prime minister Paul Martin said Wednesday that he has worked with Brown on the issue of African debt relief and considers him a "very good friend."

"He's got a huge international sense," Martin told CBC Newsworld. "I think he's going to be the kind of leader that I think we're going to need at this stage of the world."

The succession of Brown ends a partnership at the pinnacle of British politics that began when he and Blair were elected to Parliament in 1983 — sharing an office and a vision to transform their party's fortunes.

It has been widely reported — but never confirmed — that the two men made a pact over dinner in 1994, with Brown agreeing not to run against Blair for the Labour leadership following the death of then party chief John Smith.

In return, Blair reportedly vowed to give Brown broad powers as Treasury chief and to step down after a reasonable time to give Brown a shot at the senior post.

With files from the Associated Press