Long time foes Protestant clergyman Ian Paisley and former Catholic militant Martin McGuinness both vowed to work for a common future as they arrived for the landmark ceremony at Belfast's Stormont parliament building.

"We are starting on a road which will bring us back to peace and to prosperity," said Paisley, who became First Minister in the new Northern Ireland administration, with McGuinness as his deputy.

"I'm increasingly confident that all of this is going to work," added McGuinness of the Catholic-backed Sinn Fein, a former commander of its military wing, the Irish Republican Army (IRA).

British Prime Minister Tony Blair and his Irish counterpart Bertie Ahern were among those invited to the inauguration ceremony, reviving self-rule after a nearly five-year gap.

Britain's Northern Ireland Secretary Peter Hain said Tuesday's event would open a new era in the province's history.