Belfast, Northern Ireland ? Bitter enemies from Northern Ireland’s bloody past joined forces Tuesday atop a new Northern Ireland government, a once-unimaginable achievement that both sides pledged would consign decades of death and destruction to history.

The bombastic Protestant evangelist Ian Paisley, long known as “Dr. No” for his refusal to compromise with the Roman Catholic minority, formed an administration with Sinn Fein deputy leader Martin McGuinness, a veteran commander in the outlawed Irish Republican Army, which long dreamed of wiping Northern Ireland from the map.

Their long-polarized parties will jointly run a 12-member administration that took control of the territory’s government departments from Britain. Their new shared agenda: improve hospitals, schools, roads and other services and formally cooperate with the neighboring Republic of Ireland.

Power-sharing was the central goal of the U.S.-brokered Good Friday accord of 1998, a pact rejected by Paisley’s Democratic Unionist Party at the time because it included Sinn Fein. Britain and Ireland toiled to bring the factions together after 2003, when voters made them the dominant parties in the Northern Ireland Assembly, the foundation stone for cooperation.

Paisley’s conversion to compromise became possible because the IRA finally convinced him it would no longer try to oust Northern Ireland from the United Kingdom by force. The IRA renounced violence and disarmed in 2005, has not been implicated in significant violence since, and this year agreed with its Sinn Fein allies to accept the authority of the Northern Ireland police.

British Prime Minister Tony Blair, who made brokering peace a top priority since rising to power in 1997, paid particular tribute to Paisley – noting his stubborn stand had forced the Sinn Fein-IRA movement to go farther than many thought possible.

“I lost count of how many times I was told he would never accept sharing power,” Blair said of Paisley. “But he told me, in the right circumstances, that he would. He said he wanted to see Northern Ireland at peace and would not flinch from doing what was necessary to get that peace – on the only terms that he thought would endure. I believed him, and he has been true to his word.”