In the week when the pope arrives in Ireland to visit the deeply troubled Irish church, it is worth recalling the incredible deeds of an Irish Catholic priest who is definitely among the greatest Irishmen of all time.

Monsignor Hugh O’Flaherty may be one of the greatest Irish men who ever lived, yet his story is hardly known. We are not even clear about whether the Pope knows of him.

Screen great Gregory Peck was so inspired by him that he starred in a movie about him in 1983 called "The Scarlet and the Black"

At a time when Irish Catholicism is on its knees, O’Flaherty towers like an Abraham Lincoln over his contemporaries, predecessors, and successors.  He was

Ireland's Oskar Schindler.

This brave priest saved thousands of civilians and Allied soldiers during World War II. Growing up in Ireland, I never heard his tale, but I suspect I know why. He was the heroic Monsignor, based in the Vatican, who saved thousands of Allied soldiers from the Nazis and also saved hundreds of Jews from the death camps.

Perhaps because he was helping the British in the war effort, his story drew a veil of silence in Ireland but it should not have. World War II was a time for people of all backgrounds to choose sides between a monstrous evil and a force to battle that evil.

Read more: Celebrating the life of hero WW2 priest who saved thousands from the Nazis

Hugh O'Flaherty on a horse in Haiti.

Hugh O'Flaherty on a horse in Haiti.

A book I have just finished reading outlines in great detail the heroic and extraordinary efforts of a great humanitarian and Irish history.

The book is entitled “'Hide and Seek' - The Irish priest in the Vatican who defied the Nazi command" by BBC journalist, Stephen Walker.

Though an intensely proud Irishman and deeply nationalist after seeing the Black and Tans in operation during his years in the seminary, Monsignor Hugh O’Flaherty realized early on that he needed to be on the side of the good guys.

That contrasted sharply with the position taken by Pope Pius XII who dithered while the Nazis overrun Europe.

Read more: The strange history of the Nazi plans to invade Ireland

Flaherty organized the escape route for allied troops who had escaped POW camps or had been shot down but survived.

Through an incredibly close network of friends and confidantes, he set up safe houses all over Rome and in the Vatican itself where his work soon drew grave suspicion from the Nazis.

The book is a fascinating account of the stand-off between Flaherty and the head SS man in Rome, Herbert Kappler.

Kappler suspected O’Flaherty and had him under surveillance at all times. O’Flaherty comes across as a Michael Collins, however, hiding in plain sight, appearing each morning on the steps of Saint Peter's and meeting with those who were organizing the freedom runs.

Hugh O'Flaherty in Rome.

Hugh O'Flaherty in Rome.

He helped everyone who sought refuge, including many Jews, which infuriated Kappler. The SS commander tried to have O’Flaherty kidnapped with a view to summary execution but somehow O’Flaherty always managed to survive, earning him the nickname of the “Scarlet Pimpernel.”

Once, having left the neutral confines of the Vatican for a freedom route meeting, the Nazis raided the house and O’Flaherty, who was hiding in the cellar, was saved by sheer luck when two coal-men came to drop their supplies and he “borrowed” one of their outfits and strolled past the SS wearing the outfit and carrying a sack.

After the war, he was celebrated all over the world but refused most of the honors. Kappler was tried and found guilty of war crimes. Amazingly, O’Flaherty visited him frequently in prison and Kappler converted to Catholicism. O’Flaherty retired to his native Kerry for his final days and passed away there in 1963.

In a poem to celebrate his life, poet and fellow Kerry man Brendan Kennelly wrote of O'Flaherty:

"There is a tree called freedom and it grows

Somewhere in the hearts of men

Rain falls, ice freezes, wind blows

The tree shivers, steadies itself again."

The Israeli government planted a tree in his honor in 1973.

Was there ever a more courageous Irishman?

A clip from "Scarlet and the Black". The true story of Monsignor Hugh O'Flaherty:

Had you heard of Monsignor O'Flaherty's tale before?