Ookami no Kuchi: Wolfsmund

Wolfsmund is a story set in the European Alps during the beginning of the 14th century. A ruthless gatekeeper stands watch at Wolfsmund — "the Mouth of the Wolf," a fortress checkpoint at the St. Gotthard Pass going into Italy. Travelers from all walks of life try to pass through the way station, but they must first face interrogation by the gatekeeper. Things rarely end well for those who attempt the passing.
(Source: Anime News Network)
Note: Chapter count includes the chapter "Side Story: The Pope and the Swiss Guard" in volume 4.