Big news out of Toronto this week: a tiny fragment of Christ's cross was stolen from the base of a statue in St. Michael's Cathedral. Monsignor Sam Bianco chose not to call the police, because he doubted they could help, but he has offered amnestry if the thieves repent.

Odd as this caper is, the stranger story is how a church in Toronto—or anywhere—obtained a piece of the true cross in the first place.

Around the year 326, Constantine's 71-year-old mother, Helena, made a pilgrimage to Jerusalem. Constantine had recently killed his wife, Fausta, and Helena's favorite grandson, Crispus, so Helena probably sought spiritual comfort and a respite from imperial intrigue. Whatever her reasons for the journey, she made the most of it, visiting places where Jesus had walked, committing her son to building numerous churches, and engaging in some amateur archaeology. In fact, she thought that she was able to identify every important site from Jesus' life.

Eusebius (c.260-c.340), the "Father of Church History" and a friend of the imperial family, records that one of Helena's goals was to find the tomb where Jesus had been buried. No one could remember for sure where it was, but Helena finally found a Jewish inhabitant of the city who said he had learned the location from his ancestors. The site was hidden under new construction "done by atheists and impious men" and featured a temple of Aphrodite, which Helena ordered torn down. Underneath she found a cave. She notified Constantine, and he told the bishop of Jerusalem to construct a church over the sepulchre, sparing no expense.

According to accounts written some decades after Helena's death in 333, however, Eusebius completely missed the real story. Later fourth century reports from Christian ...