WASHINGTON - Joe Biden, the talkative senator known for foreign policy expertise and a command of Washington's ways, became the 47th vice-president of the US .
That marked one half of the transition of power, capped a short time later when Barack Obama took his own oath before a crowd watching on site and around the globe yesterday.
Elections are not built around or decided by running mates.
But his ascendancy to the vice-presidency is a major turning point for the country too as Biden replaces Dick Cheney, who assumed huge powers under President George Bush.
Cheney was a major voice on war and harsh interrogation techniques of suspected terrorists, and insists the Bush administration kept the nation safe. Biden accused him of doing more harm than any elected official in recent memory in "shredding the constitution".
All that will quickly be history, but Biden expects to play his own active role. The vice-presidency is open to be shaped by the person in the job - and his boss. The most important role, of course, is that Biden assumes the presidency if Obama is unable to serve.
"This is a partnership. He's president of the US, but as I said to him, 'Barack, don't ask me unless the reason you're asking me is you're asking me for my judgment," Biden said. "I said, 'I get to be the last guy in the room when you make every important decision. You're president. Any decision you make, I will back.'" - Sapa-AP