From Widow’s Weeds blog:

Chosroes II, King of Persia, had, in his sweep through Palestine, conquered the city of Jerusalem and, among other things, stolen the True Cross. Magundat, a soldier in the Persian army, was curious to know just what was so important about an old piece of wood that they must risk their lives to take it. Conquering a country is one thing. Looting and exacting tribute from the inhabitants is one thing, and actually rather enjoyable. But to put oneself in harm’s way for an old piece of wood? Where’s the sense in that?

His mind exercised by this problem, he did not stop until he had received enough information and instruction to cause him to convert to Christianity. He left the army, was baptized, taking his name Anastasius, and eventually became a monk in Jerusalem – the same place he and his friends had pillaged seven years before.

After seven years in the monastery, he found that it was again time for him to put himself in harm’s way for that same piece of wood. He went to Caesarea to visit the Holy Places and preach, but once there, he berated his countrymen for being such fools as to believe in magic and worship fire. This didn’t go over well. Christians were grudgingly accepted in the Persian empire (they had freedom of worship), as long as they confined themselves to their worship spaces and didn’t bring their religion into the public square. Anastasius  was arrested and put to heavy labor under horrible conditions to make him abjure his faith, and when that didn’t work, was sent back to Persia where seventy more Christians were awaiting death, and his tortures increased. This still did not make him turn, even with the added inducements of high government positions.

They even told him he could go back to the monastery and be a secret Christian, if only he would publicly renounce Christ. Not even these incentives could move Anastasius, and he was finally strangled to death and then decapitated. He died in 628.