BOSTON (Reuters) - The openly gay U.S. Episcopal bishop at the center of the Anglican church’s global battle over homosexuality, has entered into a civil union with his longtime partner at a private ceremony.

About 120 guests gathered at St. Paul’s Church in New Hampshire for Saturday’s ceremony for Bishop Gene Robinson and his partner of more than 19 years, Mark Andrew. The event was kept private out of respect for next month’s worldwide Anglican conference, Robinson’s spokesman, Mike Barwell, said on Sunday.

“It was absolutely joyful,” Barwell said by telephone. “A lot of his supporters and friends were there, including many members of the gay and lesbian community.”

The 77 million-member Anglican Communion, a global federation of national churches, has been in upheaval since 2003 when the Episcopal Church consecrated Robinson as the first bishop known to be in an openly homosexual relationship in more than four centuries of church history.

The Episcopal Church is the U.S. branch of the worldwide Anglican Communion.

Disputes over scriptural authority, the blessing of gay unions and other matters have become a worldwide issue and threaten turmoil this summer when Anglicans gather for their once-a-decade Lambeth Conference in Britain.

Robinson has in the past received death threats and wore a bulletproof vest under his vestments at his consecration in 2003. Two uniformed police officers stood guard at Saturday’s ceremony in the state capital Concord, said Barwell.

Robinson and Andrew held two ceremonies -- a non-religious one in which they became legal partners followed by a formal church service to give blessings to God for their relationship.

Robinson, 61, a divorced father of two, praised New Hampshire’s lawmakers when they passed legislation last year to make the state the fourth in the country where same-sex civil unions are legal. The law took effect January 1.

Robinson has suggested states go further and follow Massachusetts, which in 2003 became the first U.S. state to legalize gay marriage.

Robinson has said he wanted to enter into the civil union before leaving for England to ensure Andrew and his two daughters had legal protections given the threats to his life.

Civil unions grant largely the same state rights as married couples -- from insurance coverage to tax benefits and hospital visiting rights -- but lack the full, federal legal protections of marriage.

Robinson has been excluded from the Anglican Communion’s Lambeth Conference but plans to attend as an outside observer.