David Miliband, former environment secretary, was on Thursday named as Britain's new foreign secretary as Prime Minister Gordon Brown unveiled his Cabinet a day after assuming the charge of the high office.
Former foreign secretary Jack Straw was named as secretary of state for justice and Lord Chancellor Jacqui Smith as home secretary and Alistair Darling as chancellor of the exchequer.
41-year-old Miliband, close to former prime minister Tony Blair, was once tipped to run against Brown for the top job and is still seen as a possible future leader of the Labour Party.
He said he was "honoured and delighted" and described the Foreign Office as "a unique global asset for Britain."
Darling, who has been made chancellor of the exchequer, the portfolio held by Brown for a decade before his elevation as prime minister, was secretary of state for trade and industry in the Tony Blair ministry.
Jack Straw, the leader of the Commons in the outgoing ministry, was Brown's campaign manager.
Brown's closest political ally Ed Balls will be the newly-created schools and children secretary.
Des Browne has been appointed defence secretary while Alan Johnson has been named health secretary.
While John Hutton will be secretary of state for business, enterprise and regulatory reform while Mark Malloch-Brown, who has been conferred a peerage by the Queen on Thursday has been made minister for Africa, Asia and UN.
The deputy prime minister's post has been abolished.
Brown has also created three new departments: the department for children, schools and families, the department for business, enterprise and regulatory reform and the department for innovation, universities and skills.
New Cabinet faces include James Purnell, who takes over as culture secretary from Tessa Jowell and Andy Burnham, who becomes chief secretary to the treasury.
Douglas Alexander, who was named as Labour's general election coordinator at the weekend, takes over at the department for international development, which is expected to be given an enhanced role under Brown.
Several heavyweight figures in predecessor Tony Blair's Cabinet who did not find a place in Brown's Cabinet include former home secretary John Reid and foreign secretary Margaret Beckett.