Interesting take on "Pious"

Whereas under the Merovingians a monastery might be considered a royal monastery if it enjoyed special privileges from the kinds and queens, in the Carolingian era the giving of gifts went the other way: monasteries were expected to make gifts to the kings. This expectation was spelled out at Aachen in 819, when Louis the Pious ordered twenty-five Frankish monasteries to give him dona--an order also extended to dozens more monasteries in the Midi and east of the Rhine. For each Louis indicated whether each owed him dona, dona plus military service, or merely prayers for the royal family. Even here it was clear: those prayers were owed, not just something the monks were glad to offer.

The military service was indeed expected not just of monasteries but of bishoprics. A generation later Hincmar or Reims tried to justify churches' property holdings--which he recognized was contrary to the New Testament account of early Christians getting rid of all their possessions--in part by noting that Frankish churches were obligated to provide military service to the state. This obligation cost a church, he estimated, a fifth of its income to pay for its soldiers, because they were not given a stipend "from public resources." Such military service seemed perfectly normal to Hincmar; it was what the Carolingians required.

Things have been worse from time to time.

How did it start?

"A Merovingian king was concerned about the "illegal attacks by evil men" on
a monastery and placed it under the protection of his mayor of the palace, sub mundeburde del defnsione. ... The concept that mayors of the palace would exercise such "protection" was immediately taken up, even without an illegal attack by evil men."