SAVANNAH, Ga. - The report took 23 years to compile, with each of its nearly 500 pages individually notarized to ensure authenticity, before the Rev. Conrad Harkins carried it across the Atlantic Ocean in a box sealed by the Catholic Diocese of Savannah.

The Rev. Harkins arrived at the Vatican with the package in late March. After 410 years, five Spanish missionaries slain by Guale Indians on what's now the Georgia coast were on the path to possible sainthood. The documents delivered by the Rev. Harkins make up the official case urging the Roman Catholic Church to recognize the five Franciscan friars, killed in 1597, as martyrs - a first step toward having them canonized as saints.

"These people were regarded as martyrs when they died," the Rev. Harkins said. "This case, despite the amount of time it has taken, is really very simple. You're either going to accept the historical documents or you're not."

A historian at Franciscan University in Steubenville, Ohio, the Rev. Harkins has overseen years of research into the friars' lives and deaths as vice postulator in the cause for their beatification.

Though the friars died centuries ago, researchers have uncovered original documents that tell the story of their deaths in detail, including letters to King Philip III written after the slayings and records of the subsequent investigation by the governor of Spanish Florida.

Friar Pedro de Corpa had spent a decade before his death in the late 16th century as a missionary converting Indians to Christianity in Spanish Florida, which then included the 100-mile Georgia coast.

De Corpa was assigned to a mission near present-day Darien, Ga., when he infuriated the nephew of a Guale chieftain who planned to take a second wife. The friar admonished the nephew, a baptized Christian named Juanillo, and told him polygamy violated God's law.

On Sept. 14, 1597, Juanillo led warriors smeared in war paint to de Corpa's hut, where he was preparing for morning Mass. They killed the friar with stone clubs, severed his head and displayed it on a pike by a nearby river landing.

The warriors killed four more friars - Blas Rodriguez, Miguel de Anon, Antonio de Badajoz and Francisco de Verascola - at St. Catherines Island and other nearby missions over the next several days.

Beatification by the church, a lengthy process likely to take many years, would entitle the five friars to be called "blessed." But it requires proof of a miracle or martyrdom, meaning they died willingly at the hands of religious persecutors.

The Rev. Harkins says it should be "an open and shut case."

If he's right, the friars would join a list of only three Christians the church recognizes as having been martyred within U.S. borders.

The U.S. can claim just eight Catholic saints. Among them are the only beatified martyrs slain on American soil: three Jesuit priests killed in the 1640s by Iroquois Indians near present-day Auriesville, N.Y.

"In North America, we haven't had periods of persecution," said Lawrence S. Cunningham, a University of Notre Dame theology professor and author of the book A Brief History of Saints. "You're not going to find any martyrs in the U.S. after the period of early exploration."

A key question is whether the Vatican will view the friars, who were slain in a dispute over polygamy rather than because they were Christians, as true martyrs.

Mr. Cunningham said there's some precedent for ambiguity in the church's definition of martyrs. Some have been beatified because they died upholding Christian values rather than out of hatred for the faith.

Bishop J. Kevin Boland, who heads the Diocese of Savannah, said the friars' defense of marriage resonates strongly today because of debates over same-sex marriage.

"Death resulted because of their unwillingness to water down the teaching of the faith," Bishop Boland said. "It's very timely in today's culture, where marriage is under horrendous attacks."