January 27 -- Feast of Saint Julian of LeMans

Gauls!

Julian was a fourth century Roman patrician sent to evangelize the Cenomani, a semi-independent Gallic tribe.  They weren't politically independent, of course -- Julius Caesar had subjugated the area long ago.  But they wore their hair in long braids and ate wild boar and all the things you read about in Asterix and Obelix comics.  Religiously, some had adopted the Roman Pantheon while others stuck with the Druidic faith.  Julian had his work cut out for him.

The big conversion happened during a drought.  The Cenomani were desperate for water, so Julian took his staff, hit a rock, and a spring gushed forth.  In gratitude, King Defensor (not very Gallic, I know) of the Cenomani accepted baptism and offered part of his palace (a relative term) as a cathedral (another relative term).

Instant Christians. Just add water. 

Not everyone was sold on the new faith, though.  Julian had to keep the miracles coming to win over the whole group.  Hey bishop, raise Ortecorix from the dead, would you?  Oh, Julian, I think my daughter has demons again.  Would you drive them out for her?

Nice cathedral you've got there, Julian.

When he wasn't engaging in supernatural feats, he dedicated much time to caring for the old, the infirm, and orphans.  This is an entirely credible hallmark of his tenure as bishop, and probably accounts for as many conversions as the miracles.

He retired to a hermitage when he felt he wasn't up to bishoping anymore.  Upon his death, a massive funeral was held and a church was built over his burial site within the century, suggesting local veneration as a saint.

King Henry II was born in LeMans and baptized at the Cathedral of Saint Julian, which accounts for the English churches that bear his name.