Somewhere in my geriatric memory bank, I recall accounts of churches being burned after all the doors were shut from the outside to prevent those inside from escaping. Maybe it was during the Crusades. Whenever. Could be that time again.
It sounds like the Albigensian Crusade: southern France and northern Italy, early 1200s.
Shown in the movie The Patriot.
A church full of people locked inside was burned in the movie THE PATRIOT.
Southeastern France. Early 13th century AD.
https://en.wikipedia.org/wiki/Albigensian_Crusade
from the article:
“The Crusaders captured the small village of Servian and then headed for Béziers, arriving on July 21, 1209. Under the command of the papal legate, Arnaud Amalric, they started to besiege the city, calling on the Catholics within to come out, and demanding that the Cathars surrender. Neither group did as commanded. The city fell the following day when an abortive sortie was pursued back through the open gates. The entire population was slaughtered and the city burned to the ground. It was reported that Amalric, when asked how to distinguish Cathars from Catholics, responded, “Kill them all! God will know his own.” Historian Joseph Strayer doubts that Amalric actually said this, but maintains that the statement captures the “spirit” of the Crusaders, who killed nearly every man, woman, and child in the town.”
“Amalric and Milo, a fellow legate, in a letter to the Pope, claimed that the Crusaders “put to the sword almost 20,000 people”. Strayer insists that this estimate is too high, but noted that in his letter “the legate expressed no regret about the massacre, not even a word of condolence for the clergy of the cathedral who were killed in front of their own altar”. News of the disaster quickly spread and afterwards many settlements surrendered without a fight.”
(Never underestimate the power of making an initial good, solid “Example” to encourage quick compliance on the part of the rest of the rebels.)